Added support for pandas installed directly from git trunk

pandas.version == commit_hash when pandas is installed from git trunk
Use pandas.version.short_version
Merge pull request #1185 from invisibleroads/patch-1

BLD: Add support for installing when pandas is a shallow clone.
DOC: Fix typo. Closes #1327.
Merge pull request #1330 from jseabold/fix-1327

DOC: Fix typo. Closes #1327.
BUG: Decode metadata to utf-8. Closes #1326.
Merge pull request #1329 from jseabold/fix-1326

BUG: Decode metadata to utf-8. Closes #1326.
ENH: Always use unicode.
Merge pull request #1331 from jseabold/dataset-unicode-docstrings

ENH: Always use unicode.
ENH: Add Bunch object to tools.
Merge pull request #1332 from jseabold/add-bunch-obj

ENH: Add Bunch object to tools.
STY: __all__ should be after imports.
Merge pull request #1333 from jseabold/cleanup-all

STY: __all__ should be after imports.
REF: Get rid of plain assert.
Merge pull request #1336 from jseabold/assert-clnup

REF: Get rid of plain assert.
simple typo fix
freudian typo strife vs. strive?

Was this intended, do you guys fight about using TDD? :)

[1] http://www.thefreedictionary.com/strife
[2] http://www.thefreedictionary.com/strive
fix years for GSOC
Merge pull request #1339 from esc/fix_typos

Fix typos in intro
ENH: Convenience function for order selection by IC