Remove gc_upload.py

We use GitHub now rather than Google Code
and Google Code is deprecating supporting file uploads anyway.
print_freetds_version.py => print_versions.py

The latter is more general, as it prints out:

  - _mssql.__version__
  - pymssql.__version__
  - pymssql.get_dbversion()
Get PYMSSQL_VERSION from pymssql_version

instead of duplicating and having inconsistency
MANIFEST.in: Include pymssql_version.py

so tox tests don't fail
pymssql_version.py: Change version to 2.0.1.1

so that sqlalchemy test doesn't fail on non-numeric version number.
New scheme for managing version

Instead of depending on runtime import of pymssql_version.py,
we store version in pymssql_version.h and compile it into pymssql.pyx
and _mssql.pyx and extract the version for setup.py
_mssql.pyx: Prevent error string growing

with repeated failed connection attempts.

Fixes GH-145
Merge pull request #146 from pymssql/issue_145_prevent_error_string_accumulation

_mssql.pyx: Prevent error string growing
pymssql.pyx: Minor tweaks to comment about apilevel
_mssql.pyx: Zero init global last_msg_* vars

Otherwise they can have random garbage in them.

 cdef char *_mssql_last_msg_str = <char *>PyMem_Malloc(PYMSSQL_MSGSIZE)
+_mssql_last_msg_str[0] = <char>0
 cdef char *_mssql_last_msg_srv = <char *>PyMem_Malloc(PYMSSQL_MSGSIZE)
+_mssql_last_msg_srv[0] = <char>0
 cdef char *_mssql_last_msg_proc = <char *>PyMem_Malloc(PYMSSQL_MSGSIZE)
+_mssql_last_msg_proc[0] = <char>0
Merge pull request #152 from pymssql/clear_zero_init_global_mssql_last_msg_stuff

_mssql.pyx: Zero init global last_msg_* vars
Travis won't work for PRs from forks: make clear

Make Travis CI fail if "$TRAVIS_SECURE_ENV_VARS" = "false"
Merge pull request #154 from pymssql/make_travis_failure_for_pr_from_fork_more_obvious

Travis won't work for PRs from forks: make clear
Sphinx-based documentation.

This is a combination of 23 commits:

More reST markup.

Add project history document (ported from Google Code wiki).

Reformat for readability. Typos. Small reST tweaks.

Port another couple of docs.

Add build dir to Git ignore list.

Correct pymssql class names.

Implement new RTD HTML theme.

Link module references from main page body.

Add statement about Python 3 and Unicode. Stolen from psycopg2 docs :)

Further content re-shuffle and refactor.

Add 'quickly-contribute-to-pymssql-docs-via-GitHub-PR' link to each page.

Include content from up-to-date reST files at project root. Refactor.

Add note + link to 1.x documentation wiki.

Add Marc to 2.0 credits.

Update year in &copy;

Expand pymssql reference. Also, tweak it and _mssql's

Main page tweak.

Add docs To-do items. Use sphinx.ext.todo for this.

Add code-block directive so _mssql exception handling example gets
syntax highlighting

Prepare for publishing at the Web site.

Use 'seealso' reST directive.

Update packaging files for docs.