Relicence EasyMotion under MIT licence

- close #194
- ref https://github.com/haya14busa/haya14busa/issues/13#issuecomment-62876100

doc/easymotion.txt

@@ -1068,9 +1068,27 @@ and their default values.
 ==============================================================================
 License                                                    *easymotion-license*
 
-Creative Commons Attribution-ShareAlike 3.0 Unported
+License: MIT license
 
-http://creativecommons.org/licenses/by-sa/3.0/
+Copyright (c) 2014 Kim Silkebækken, haya14busa
+
+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.
 
 ==============================================================================
 Known bugs                                              *easymotion-known-bugs*