Added initial .gitignore
Add support for ignoring dist files by extension.

 * When using pip, .exe and .egg dists being included in an
   index page slows retrieval down.  This patch adds configurable
   support for ignoring dist files by extension.
 * Configure by adding a comma-separated list of extensions to
   ignore:

   [eggproxy]
   ignored_extensions = .egg, .exe
Merge remote-tracking branch 'mauran/speedup-pip'