remove obsolete test cases
refactoring: move AST helper classes to CRewrite package where it is used

These classes have nothing to do with AST parsing and are not necessary
for type checking. The navigation support is used only within CRewrite,
hence moving classes there into separate package.
(Those classes contain lots of warnings which are also better isolated now)
Might be moved into separate subproject eventually if shared by multiple
other subprojects that do not need CRewrite

Also turned EnforceTreeHelper from a trait into a an object providing
the same helper functions

Also rewrote IntraCFGFileTests slightly to make code more readable
improve readability of test code
removed unused fields
introduce option for call graph in addition to CFG (no implementation added yet)
refactoring for readability
normalize whitespace
documenting types more explicitly and renaming CFG -> SuccessorList
refactoring for readability
rename SuccessorList to NextNodeList
remove CRefactor subproject.

to be reintroduced as a separate project later.
(the current version here was outdated and maintained elsewhere in Andi's
fork)
minor refactoring for code readability

use Scala idioms getOrElseUpdate
renaming to avoid compiler error

name clash in two traits
fix typo
fix bug introduced in refactoring
infrastructure for all graphs and call graph comparison
extra tests -- for the test infrastructure
Merge pull request #28 from ckaestne/CallGraph

Refactorings