Merge pull request #15 from tyro89/master

fix write for very large files.
Version bump to 0.10.5
Regenerate gemspec for version 0.10.5
Use a Mutex to synchronize the usage of the connection.
Small mutex handling improvements
Fix busy? and ready_for_query?, and add a test for concurrent access.
Merge pull request #16 from sprsquish/mutex

Use Mutex to grant exclusive access to connection
Version bump to 0.11.0
Regenerate gemspec for version 0.11.0
Move from jeweler to bundler for gem management tasks.

- Update to best practices
- Rely on bundler in development environment.
Convert test suite to minitest.
Remove 18 compatibility code as it stopped working a while ago.
Remove defensive programming check for internal API.
README tweaks.
README improvements.
Small README fixes.
More README changes.