Use MIT license

Tom Preston-Werner's keynote at OSCON 2013 convinced me that the MIT
license is the proper license for this plugin.

.gitignore

@@ -2,6 +2,7 @@
 
 !.gitignore
 !CONTRIBUTING.md
+!LICENSE
 !README.md
 !autoload/sy.vim
 !autoload/sy/debug.vim

LICENSE

@@ -0,0 +1,20 @@
+The MIT License (MIT)
+
+Copyright (c) 2013 Marco Hinz
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

README.md

@@ -224,5 +224,4 @@ Marco Hinz `<mh.codebro@gmail.com>`
 License
 -------
 
-Copyright © Marco Hinz. Distributed under the same terms as Vim itself. See
-`:help license`.
+MIT license. Copyright (c) 2013 Marco Hinz.

doc/signify.txt

@@ -302,9 +302,6 @@ Israel Chauca Fuentes  (Raimondi)
 ==============================================================================
 8. Licence                                                     *signify-license*
 
-Copyright © Marco Hinz. Distributed under the same terms as Vim itself.
-
-See |license|.
-
+MIT license. Copyright (c) 2013 Marco Hinz.
 
 vim: tw=78