DNN-3759 Add Syntax Highlighting code editor
DNN-3759 Add Syntax Highlighting code editor

Incorporated the CodeMirror syntax highlighting code editor.  Added a custom CodeMirror theme
which more closely mimics the colors from SQL Server Management Studio.  There are some
additional improvements that could be made to the SQL mode to more fully support the T-SQL
dialect.

RichardHowells/Dnn.Platform,valadas/Dnn.Platform,svdv71/Dnn.Platform,SCullman/Dnn.Platform,AugustKarlstedt/Dnn.Platform,valadas/Dnn.Platform,wael101/Dnn.Platform,wael101/Dnn.Platform,ohine/Dnn.Platform,moshefi/Dnn.Platform,nvisionative/Dnn.Platform,moshefi/Dnn.Platform,bdukes/Dnn.Platform,abukres/Dnn.Platform,51Degrees/Dnn.Platform,bdukes/Dnn.Platform,JoshuaBradley/Dnn.Platform,mitchelsellers/Dnn.Platform,AugustKarlstedt/Dnn.Platform,51Degrees/Dnn.Platform,51Degrees/Dnn.Platform,bdukes/Dnn.Platform,svdv71/Dnn.Platform,ohine/Dnn.Platform,RichardHowells/Dnn.Platform,abukres/Dnn.Platform,wael101/Dnn.Platform,abukres/Dnn.Platform,ohine/Dnn.Platform,moshefi/Dnn.Platform,RichardHowells/Dnn.Platform,dnnsoftware/Dnn.Platform,nvisionative/Dnn.Platform,ohine/Dnn.Platform,EPTamminga/Dnn.Platform,mitchelsellers/Dnn.Platform,nvisionative/Dnn.Platform,EPTamminga/Dnn.Platform,mitchelsellers/Dnn.Platform,51Degrees/Dnn.Platform,mitchelsellers/Dnn.Platform,mitchelsellers/Dnn.Platform,dnnsoftware/Dnn.Platform,janjonas/Dnn.Platform,EPTamminga/Dnn.Platform,AugustKarlstedt/Dnn.Platform,raphael-m/Dnn.Platform,dnnsoftware/Dnn.Platform,JoshuaBradley/Dnn.Platform,RichardHowells/Dnn.Platform,valadas/Dnn.Platform,dnnsoftware/Dnn.Platform,JoshuaBradley/Dnn.Platform,raphael-m/Dnn.Platform,dnnsoftware/Dnn.Platform,raphael-m/Dnn.Platform,bdukes/Dnn.Platform,valadas/Dnn.Platform,robsiera/Dnn.Platform,yiji/Dnn.Platform,svdv71/Dnn.Platform,yiji/Dnn.Platform,robsiera/Dnn.Platform,robsiera/Dnn.Platform,raphael-m/Dnn.Platform,AugustKarlstedt/Dnn.Platform,SCullman/Dnn.Platform,janjonas/Dnn.Platform,SCullman/Dnn.Platform,yiji/Dnn.Platform,janjonas/Dnn.Platform,valadas/Dnn.Platform