Migrated to git!

- Added git guide for ZF1
- Updated README, INSTALL, and DEVELOPMENT_README to reflect move to git
  - README indicates origins in subversion
  - README includes directions for both git and subversion, and subversion
    points to old SVN server as well as GitHub URIs
- Updated composer.json to reflect branches available
Made readme a markdown file
Minor markdown style updates
Merge pull request #1 from zendframework/master

Migrate to Git