Update version strings: 1.2.0 to 1.2.0-dev

Fixes #193.
Merge pull request #204 from jrrideout/1.2.0-post-release

Update version strings: 1.2.0 to 1.2.0-dev
Add parse_mapping mention to ChangeLog
Merge pull request #206 from jrrideout/1.2.0-changelog

Add parse_mapping mention to ChangeLog
Removed R-code subdir, and updated index.rst with links.

This contributes to [Issue
211](https://github.com/biom-format/biom-format/issues/211).

https://github.com/biom-format/biom-format/issues/211
added extra colons
Merge pull request #214 from joey711/rm-R-biom

Removed R-code subdir, and updated index.rst with links.
Initial work on scipy.sparse backend

Some very basic stuff is working, still needs a lot of other things implemented.
Implement more core methods

Including:

- getRow/getCol
- transpose
- copy
- items
- iteritems
Add __eq__ and __ne__
Add __setitem__ and __getitem__
Make shape and dtype properties

Instead of attributes
Add conversion factories
Add ScipySparseMat to backend loader
Add missing imports
Add support for empty sparse matrices.

Ugly but necessary...
Remove zeros in data cleansing step

All tests now pass. We have an efficiency warning to still take care of.
Add lil conversion for efficiency

Tests all pass without any warnings!
Add results fp option to bench.sh

Also reports errors when running bench scripts
Fix several bench scripts

Many were erroring out, likely due to changes in biom-format API since they were originally written.