Add boto subdirectory to gitignore.
Update gsutil CACERTS_FILE_SHA1SUM file per new boto cacerts.txt content
Uncomment gsutil cp -v tests for copy-in-the-cloud now that that mechanism works
Refactored all third party libraries.

There are now two third_party directories. The root directory /third_party is
meant for third-party (i.e., non-gsutil) libraries that are required by gsutil
but may be obtained by a Python package manager (e.g. pip or easy_install). The
gslib/third_party directory is a Python module that contains submodules with
third-party libraries required by gsutil that are not obtainable with Python
package managers.

* Added boto library as a submodule in /third_party.
* Moved retry_decorator, fancy_urllib, and oauth2_plugin to gslib/third_party.
* Removed boto_lib_dir parameter passing through to Command classes.
* Changed gsutil to add /third_party to the path instead of boto.
* Added @Retry to a flaky rm test.
Changed test_rm retry to be more robust to failures.
Merge pull request #127 from jterrace/third-party-refactor

Refactored all third party libraries.
Updated VERSION to 3.25
Added --help support to subcommands. Fixes #96.
Updated documentation to include submodules and changed README to markdown.
Output more bucket metadata on ls -Lb
Fixed problem where gsutil -m is hard to interrupt (only for Linux/MacOS; problem still exists for Windows)
Renamed gsutil meta_generation params to metageneration, for consistency with GCS docs
.
Fixed broken reference to boto_lib_dir in update command.
Add a test for the update command.
Fixed bug where gsutil cp -D didn't preserve metadata
Changed gsutil to check for available updates periodically
Update gsutil help docstrings for RST generation compatibility.
.
Added note to gsutil update help that automatic software update checks aren't performed when stdin/out/err aren't connected to a TTY