Steamodd

This release introduces some changes that my or may not require changes to code depending on how you use steamodd but will not break anything (hence no major release).
- Removed some optf2-specific cruft that made `item.full_name` overwrite the item's normal name if there was a custom name attached and append a craft number if present. These two things are easy to replicate by code using it, but building standard names properly are not.
- Added some minor fixes for compatibility with older python versions
- Catch top level URLError being used by urllib for timeouts(!).
- Tests now also ran against pypy

This is mostly a release keeping up with Valve's ever-changing ways of messing around with the schema and a feature for running tests with custom runners easier.
- Clean up attribute value formatter and avoid potential incompatible encoding
- Check to see if an attribute value stored in the int field isn't a float before trying to cast to int (Valve likes to store floats there occasionally)
- Add support for using STEAMODD_API_KEY env var instead of having to call `steam.api.key.set` manually.

Codename: **Steamodd Takes Valve's Hate So You Don't Have To!**

This fixes a rather hard to spot but still annoying bug that made me have to break out ol' pdb for the first time this month. Also did some changes to the unit tests.
- Fixed over-optimization in attribute builder that sometimes caused the schema's attributes to get overwritten
- Remove redundant error message in testitems
- Strip crate series in item name test (a Valve-ism that isn't related to proper naming, similar to craft numbers)

This is a release that adds a workaround to a recent update where Valve started putting strings as attribute values. I don't know how to handle this at the moment without a major release and making people change code so for the moment it will merely return 0 for these attributes. Which are currently for custom names and descriptions. Information already available via `item.custom_name` and `item.custom_description`.

An employee has told me that this is intentional. So I suppose the bug is steamodd's.

This is mostly a feature release with a few fixes.
- Added rst long description for PyPi
- Added batch profile support (`steam.user.profile_batch`)
- A new test fixture for aforementioned support and fix to make the status code what it should be
- Some comment fixes by Smashman
- The first ever steamodd release codename: **Fork Freeman**