Improved preview and added support for settings file

Significantly improved the preview functionality.
Added feature to remove any non-existent files from the history when previewed or opened.
Added use of settings file to retrieve user preferences:
* history_file: Path to store the history entries in (relative to the sublime packages path)
* global_max_entries: Maximum number of history entries we should keep (older entries truncated)
* project_max_entries: Maximum number of history entries we should keep (older entries truncated)
* use_saved_position: If we should try to use the saved position of the file or blindly use the "new_tab_position" setting
* new_tab_position: Which position to open a file at when the saved index in no longer valid ("next", "first", "last")
* show_file_preview: Should we show a preview of the history entries
* remove_non_existent_files_on_preview: Remove any non-existent files from the history (when previewed or opened)
* debug: Print out the debug text?
Default settings FileHistory.sublime-settings
re-added accidentally deleted header
Added cleanup on start up and bug fix
Added cleanup_on_startup setting
Quick open a history entry with tab
Quick open a history entry with tab
Added "quick open" history entry support
Update file_history.py
Fixes to support quick open using right" key
updated mapping for quick open with "right"
updated mapping for quick open with "right"
Event on on_pre_close rather than on_close

Also some code cleanup
Removed test code used to test settings creation
Added default "use_monospace_font" setting (false)
Updated with new features
Fixed incorrectly formatted link
Added v1.3.5
Updated summary text
Updated version number