Binaries release with 'csearch -M' and 'cindex -filelist' support

v3

More prebuilt platforms; saner flags; better help

• Move to simpler release tags.
• Change -follow-symlinks flag to -no-follow-symlinks as -follow-symlinks is the default.
• Made prebuilt binaries work on all platforms.
• Better cgrep help.

First binaries release

This release contains the following changes over the original codesearch.

1. Don't just ignore a file just because it has a few non-UTF-8 characters (controllable via the -maxinvalidutf8ratio option).
2. Support for file exclude patterns via $HOME/.csearchignore.
3. Support for limited search results for speed for IDEs/Editor plugins (e.g. by the unite-codesearch vim plugin) via -m MAXCOUNT option.
4. A -0 option to allow easier shell scripting use with the xargs utility.
5. An -indexpath option for overriding $CSEARCHINDEX.
6. Higher default trigram and file size limits controllable via -maxtrigrams and -maxfilelen respectively.
7. symlinks are followed by default. This is overridable via the -follow-symlinks=false.
8. Improved documentation.