Changing "Underline" button to display "U" instead of "S"
("S" more often refers to strike-through than underline)
Merge pull request #58 from dcollien/master

Changing "Underline" button to display "U" instead of "S"
Version 1.1.4
Updates screenshot and README
enable basic button set customization
Optionally allow an array of button names. This 
allows exclusion of some buttons, plus
reordering.
fixes the linking failures
tests: remove excludeActions, add buttons default
remove excludedActions
update docs to reflect excludeActions/buttons
Merge pull request #60 from pixelpony/master

enable basic button set customization
1.1.5
Merge branch 'master' of github.com:daviferreira/medium-editor

Conflicts:
	dist/js/medium-editor.js
	dist/js/medium-editor.min.js
	spec/init.spec.js
	src/js/medium-editor.js