Fix compiler errors for GCC 2.8

Related to #71
Initial commit of ArtForm mode (currently empty)
Move concolic tests to system test harness
Add support for form inputs using name in concolic mode.

References #70
Filter out "Other" navigational requests since we suspect these to be non-navigational in practice.

Fixes #73
CLEANUP: Change memory model for DomElementDescriptor
CLEANUP: Simplify forminput related classes
New simplified trace display mode reduces the size of large graphs.
Merge branch 'feature-path-exploration' of github.com:cs-au-dk/Artemis into feature-path-exploration
Merge branch 'feature-path-exploration'

Conflicts:
	WebKit/Source/JavaScriptCore/wtf/HashMap.h
	WebKit/Source/JavaScriptCore/wtf/Vector.h
GCC 4.8 support

Fixes #71