Flowcal

This version fixes minor bugs and improves compatibility with respect to version 1.1.0.

Bug fixes
- FCSData now loads fcs files successfully when the file contains information on `$PnG` and `$PnV` other than numbers.
- Linear gain in specific files generated by FlowJo Collectors Edition is now properly extracted.
- `FlowCal.gate.start_end()` now behaves as expected when `num_end=0`.
- `plot.scatter3d()` now works with matplitlib 1.5.1.

Code improvements
- `FlowCal.excel_ui.process_beads_table()` and `FlowCal.excel_ui.process_samples_table` now plot to the standard output when `plot_dir` is not specified.
- `excel_ui.process_beads_table()` now contains an additional argument to directly control `mef.get_transform_fxn()`.

High-level changes
- Improved compatibility with different FCS files.
- Improved ability to handle high-resolution FCS data and floating-point data, and transform this data to MEF.
- Logicle scale implemented. This is the new default for plotting.

Important code changes

Gating and plotting
- `gate.density2d` and all simple plotting functions now include arguments `xscale`, `yscale`, and `zscale` as appropriate, to define the scale of each axis. Valid options are `'linear'`, `'log'`, and `'logicle'`. All these functions default to `logicle`.
- Arguments `log`, `xlog`, `ylog`, and `zlog` in plotting functions are deprecated.

I/O
- `FCSData` property `domain` has been deprecated. New function `range` returns, for each specified channel, the lower and upper bounds as specified by the FCS file.
- `FCSData` property `hist_bin_edges` has been deprecated. New function `hist_bins` allows for dynamic generation of histogram bins using either linear, logarithmic, or logicle scaling.

MEF
- The transformation function returned by `get_transform_fxn` is now meant to be used with data previously transformed to RFI using `transform.to_rfi()`.
- Functions `clustering_gmm` and `selection_std` now allow for rescaling of the data before performing their operations. The default scaling is `logicle`.
- `fit_beads_autofluorescence` now uses a model that transforms data from RFI to MEF. Previously, the model was meant to be used to transform data in raw channel numbers to MEF, when using a logarithmic amplifier. The new approach allows for transformation of data taken with linear amplifiers as well.

Changes in Excel UI:
- Statistics for beads files, including bead model parameter, detector gain, and others.
- User-friendly error reporting for files with low event counts, non-existing files, and acquisition settings of corresponding beads and samples not identical.
- Command-line parameters for the Excel UI, which allows the user to batch-process several files, and turn on or off the generation of plots.

Changes in code:
- `transform.exponentiate()` deprecated in favor of `transform.to_rfi()`, which automatically decides whether to exponentiate the data based on acquisition settings.

Other changes:
- Bug when loading files that do not contain a valid `$DATE` keyword.

Changes in Excel UI:
- Titles in density/histogram plots produced by the Excel UI now have the sample ID instead of the file name.
- Corrected bug that interfered with the Excel UI's file selection window in OSX.

Other changes:
- Earlier versions of some requirements are now supported.

Code changes:
- Package name has been officially changed to `FlowCal`.
- Reorganized modules `plot` and `mef`.

New feaures:
- New Excel interface!
- Scripts for easy installation and launch of Excel UI .

Others:
- Code style changes.
- New unit tests.