Modified the toXMLHead and toXMLTail methodst

The two methods were returning xml start and end tags. Instead now they return s expressions.
Modified ExprCaseHandler

Modified the ExprCaseHandler class to generate s-expressions instead of xml.
Modified StmtCaseHandler
Modified the class to generate s-expressions instead of xml.
Fixed bugs for new parser
Modified FunCallExpr and AllocExpr .

The attributes being appended with the ':'. This was an issue since the toXML method was also appending a : to all the attributes.
Modified StmtCaseHandler

Break and continue were being generated as breakstmt and contstmt. Changed that to break and continue
Bug fix : StmtCaseHandler
id field in return statement passed with colon. Removed that
Merge branch 'develop' of https://github.com/Sable/mclab into develop