Plugin: Search for the first conflict in the opened views

Using sublime.set_timeout_async the plugin will now highlight the first
conflict in the file when opening a view via "Show Conflict Files".

A cursur focus doesn't work atm.
Plugin: Ensure cursor is set when opening a conflict file

 - Directly search for the first conflict in the opened view
 - Ensure the cursor is set in the new view by using sublime.set_timeout
   (Github: Sublime issue #39)
Plugin: Minor formatting and refactoring of function calls

Avoid unnecessary temporary variables and methods (_open_file_workaround)
Plugin: Refactoring of "Show Conflict Files"
Plugin: Refactor ListConflictFiles into more submethods
Plugin: Add MIT License
Plugin: Major refactoring - Move a lot of functionality into own submodules

 - conflict_re
   Contains the regular expressions which are used to find conflicts in files

 - git_mixin
   Contains the GitMixin class which in turn contains useful functions to
   easily handle the detection of git repositories and execute git commands

 - messages
   Contains all messages the plugin displays

 - settings
   Contains the logic to read the user settings and provides default values

 - util
   Contains everything else which is useful but didn't fit into a more
   specific module (atm it only contains "execute_command", a function
   which eases the work with the python subprocess module)
Plugin: Disable the search for a conflict on opening a view

Atm "show_at_centre" doesn't work properly on newly opened views and
provides inconsistent results.
Due to this I disable the feature until I'm able to find a workaround
or the bug gets fixed.

See Sublime Text issues for more information.
Docu: Add message for 1.4.7
Plugin: Fix "Show Conflict Files" cursor bug, refactor plugin structure

Bugfixes:

"Show Conflict Files" now properly adds a cursor to the newly opened
views (Fixes #9).

Major refactoring:

A lot of functionality was moved into sub modules which can be found in
the modules folder.

 - conflict_re
   Contains the regular expressions which are used to find conflicts in files

 - git_mixin
   Contains the GitMixin class which in turn contains useful functions to
   easily handle the detection of git repositories and execute git commands

 - messages
   Contains all messages the plugin displays

 - settings
   Contains the logic to read the user settings and provides default values

 - util
   Contains everything else which is useful but didn't fit into a more
   specific module (atm it only contains "execute_command", a function
   which eases the work with the python subprocess module)