Added About modal with last commit hash, moved some dialogs to lesionTracker package from viewerbase (OHIF-52)

OHIFViewer/.meteor/packages

@@ -40,3 +40,4 @@ fastclick@1.0.12
 standard-minifier-css@1.1.8
 standard-minifier-js@1.1.8
 aldeed:simple-schema
+johdirr:meteor-git-rev

OHIFViewer/.meteor/versions

@@ -46,6 +46,7 @@ iron:controller@1.0.12
 iron:core@1.0.11
 iron:dynamic-template@1.0.12
 iron:layout@1.0.12
+johdirr:meteor-git-rev@0.0.4
 jquery@1.11.9
 launch-screen@1.0.12
 livedata@1.0.18