Minor fix for symbolic variables.
Java backend: added some documentation for visitor classes
testgen: refactored a util class to be non-static
testgen: started working on a structure checker for ruling out undesired programs during generation process
Fix broken build.
simulation By Liyi Li
Java backend: minor: revised some documentation
testgen: implemented a pluggable structure checker for K AST
Merge branch 'master' of https://github.com/kframework/k
testgen: added some TODO comments; fixed a bug
testgen: replaced free variables in the final pgm with simplest possible syntactic constructs (in a cheating way)
testgen: renamed a class
testgen: implemented checker plugin for checking syntactic constructs tagged with attribute left are indeed left-assoc
Java backend: fixed a missing case in translating the "requires" part of a generic KIL node
Fix for Issue #207.

Added warning message about unused --transition tags

cink-semantics/basic$ kompile cink --transition "assign side-efect seqpoint inc"
/c/Users/Traian/Documents/k/bin/kompile: line 3: ulimit: stack size: cannot modify limit: Invalid argument
[Warning] Compiler: These specified transition tags were not used (mispelled?):
                [inc, side-efect]
        File: command line arguments
        Location: --transition
Issue #122 fixed.
add --threads parameter to ktest