Handprint

* Two bugs related to running with multiple threads (the default) are hopefully fixed in this version:
* Sometimes the annotated image generated from a given service would have the results from another service also written over it. This was inconsistent and intermittent, and the exact cause is still unclear, but this version of Handprint implements a workaround that hopefully stops this from happening.
* The Amazon service interface would sometimes fail with an error related to `endpoint_resolver`. This was due to the previous code not following recommendations about using a different connection session object in each separate thread. This is now fixed.
* This version changes the way output files are named. The new scheme always includes the string `handprint` in the file name for easier recognition and to help reduce the chances of file name collisions. The scheme uses the naming pattern `somefile.handprint.png` for
the rescaled input image, `somefile.handprint-service.ext` for the
various service output results, and `somefile.handprint-all.png` for the
summary grid image. (Issue 10.)
* PDF files are now accepted as input. (Issue 11.) Note, however, that
Handprint will only extract the first image in the PDF file.
* The order in which resizing and rescaling is done has been swapped: if a file is too large, Handprint will first rescale it, and then if it is still too big (in byte size), it will resize the file. This appears to result in images that have higher resolution than the previous approach, which did the steps in the opposite order.
* The URLs in the file of example URLs, `tests/urls/caltech-archives-urls.txt`, have become invalid. They have been replaced with other URLs that are valid (as of right now, anyway).
* A few more bugs have been fixed.

* Improve installation instructions and avoid telling people to use `sudo`.
* Add facility to compare extracted text to a ground truth file. This is enabled using the command-line option `-c`. See the README file or help text for more details.
* Add command-line option `-r` to adjust some of the behavior of `-c`. See the README file or help text for more details.
* Change the debug option `-` to accept an argument for where to send the debug output trace. The behavior change of `-` is not backward compatible.
* Internally, package metadata is now stored in `setup.cfg`. Also, there is no `handprint/__version__.py` anymore, and instead, some special code in `handprint/__init__.py` extracts package-level variables directly from the installation created by `pip`.
* Most test images have been removed from `tests/images` and put instead in a more organized fashion in a separate repository, [htr-test-cases](https://github.com/caltechlibrary/htr-test-cases/).
* Add some missing package imports.

* Fix an internal bug getting the credentials file for Amazon services.

* Fix [issue 9](https://github.com/caltechlibrary/handprint/issues/9): credentials files are not saved in expected location.
* Edit the `README.md` file.

This version adds instructions for installing from PyPI and fixes a bug writing files downloaded from URLs.

This release provides a great many changes over the previous versions of Handprint. The behavior and implementation have all changed in various ways, and collectively this marks the first version that can fairly be called version 1.0.0.

The following are some of the notable changes in this release:

* Credentials are now stored in a separate user directory; in additional, the process for installing credentials files is different, and involves invoking Handprint with the `-a` option.
* Handprint now calls services in parallel threads, to speed up processing. The number of threads can be set via the `-t` option.
* To display the results of text recognition, Handprint now creates a summary image showing all service's results in an _N x N_ grid, thus allowing easy inspection and comparison of results across services. By default, this is now the _only_ output that Handprint produces unless given the `-e` option. With `-e`, Handprint also stores the raw data from the services and the pure text output.
* Images are now always sent to HTR services in PNG format, even when a service accepts other formats. Source images will be converted to PNG if they are not already in that format. (This simplifies processing and code flow.)
* Intermediate results files are now deleted unless the `-e` flag is given, reducing clutter and confusion.
* Some additional command-line arguments have been changed in backwards-incompatible ways.
* The [tests/images](tests/images) subdirectory has been reorganized, some previous images have been deleted, and some new ones have been added
* Internal code such as [network.py](handprint/network.py) has been updated to versions developed for other projects such as [Microarchiver](https://github/caltechlibrary/microarchiver).
* There are new command-line options.
* More bugs have been fixed in the code.
* More error checking has been added throughout.
* Much of the internal code has been refactored and rewritten.
* The repository now uses [READMINE](https://github.com/mhucka/readmine) structure for [README](README.md) file.
* Added code of conduct and contributor guidelines to the repository.