inline and rewrite in a more understandable manner a method from DebugActionsUtil
refactor state and add view as action group
view as for variable tree works
remove unused classFqName which was passed around
store custom viewers by session
remove class fq name from java stack frame
store value proxy in java value
move java field
smart selection of default custom viewer
move customViewers into debugger-java plugin
turn everything into custom viewers
rename actions & do not show view as with only one wrapper
getName method for ValueWrapperFactory
remove session from map on detach
Merge remote-tracking branch 'origin/master' into 3.1/julia/debugger

Conflicts:
	plugins/debugger-java-customViewers/META-INF/plugin.xml
	plugins/debugger-java/api/jetbrains/mps/debugger/java/api/state/proxy.mps
	plugins/debugger-java/api/source_gen/jetbrains/mps/debugger/java/api/state/proxy/JavaStackFrame.java
fix exceptions, break expansion
work on variables tree expansion
fix exceptions in expanding variables tree
fix tree expansion (always call callbacks)
fix selection in the tree