Merge pull request #27 from htoothrot/master

Issue #26: Finalize FileIterator_Type to do the right thing and avoid a crash in PyPy
Change "Linux / OS X" to be more general "POSIX systems".
Mention possible improvement (free list)
Add start of "Rejected ideas" section.
Merge pull request #28 from htoothrot/master

Fix bad placement of PyType_Ready call
Add note about Paul Moore's version.
Add some rejected ideas. Change Unix -> POSIX.
Remove open issue "should scandir be in its own module", as there's general consensus it should go in the os module.
Add note about .full_name; remove open issue on whether there should be a way to do this.
Remove Windows wildcard open issue now that that's been rejected and discussed in Rejected ideas section.
Call os.scandir() rather than just scandir() in the examples.
Add section on exception handling.
Move Examples section above notes sections.
Explicitly mention bytes and str support.
Clarify implementation about when methods make system calls.
Fix single backticks for ReST syntax.
Add .full_name attribute to scandir, per recent discussion on PEP 471.
Fix error handling version of get_tree_size().
Add "Support" bullet point noting recent python-dev +1's.
Add final two "rejected ideas" sub-sections.
Merge branch 'master' of https://github.com/benhoyt/scandir
Issue #30: Get version without importing scandir because that will lock the .pyd file (if scandir is already installed) so it can't be overwritten during the install process.