Added filename completion support for grep commands. In GUI Vim, added Tools->Search menu item for using the Grep commands.
1. Add the search pattern to the search results. 2. Support for the -h argument to the commands. 3. Make the plugin work in Vi-compatible mode. 4. Updated documentation.
Support for specifying the grep flags, search pattern and filenames as argument to commands and other minor improvements.
Fixed file pattern quoting and special character escaping for MS-Windows.
