Code cleanup and bug fixing

* Fix an error in getting FunctionGroup from base class if base class
doesn't contain any function defintion.
* Code cleanup for FunctionTable
Merge pull request #15 from ke-yu/master

Code cleanup and bug fixing
Added LiveRunner API's to pass to it DS code for command-line interpreter mode of execution
Merge branch 'master' of https://github.com/lukechurch/designscript
Merge pull request #14 from junmendoza/master

Implemented save and restore of graphnode states for function calls. Regression fix for replication guide and array index propagation in SSA transformed code
Merge pull request #16 from aparajitp/master

Added LiveRunner API's to pass to it DS code for command-line interpreter mode of execution
Merge remote-tracking branch 'upstream/master'