Add new rules : UseMinOrMaxRule and UseSwapRule.
Use functions from ASTUtil.h and move some functions into ASTUtil.h
format code.
Some clean up: Fix lqi's remark about name.
some fixes according to Lqi's remarks:
rename toString into exprToString.
add empty line between include.
rename most variables in IsASwap.
Rename directory 'replace' by 'std'
- Rewrite isASwap with smaller function and support multiple declaration.
- Fix unitTest.
- give a better name for unitTest
- add TODO for "not yet supported"
Rewrite UseMinOrMaxRule.cpp
- Better names
- fix some oclint warnings.
- Use StmtVisitor to extract differences from statement.
Use Violation Tag locations in Unit Test.