added missing file (it was .gitignored)
removed OMakefiles, they are not useful in upstream
*DEBUG(x) -> DEBUG{x}

The problem with DEBUG(x) is that it expands on a single line,
reducing debug information granularity. This change has the additional
advantage that it's easier for editors to auto-indent code within a DEBUG
statement.
add AB_SWITCH macro for dispatch over absyn tag

Ultimately, all code that dispatches over all or most tags should use this
macro. Adapt the macro to fit into other use cases.
print parser traces to dbOut, not stderr
put braces around all DEBUG_IF-bodies
renamed DEBUG to phaseDEBUG and use if (DEBUG(stuff))
replace xyzDEBUG with if (DEBUG(xyz))

Also, define `xyzDEBUG` as `if (DEBUG(xyz)) afprintf`.
In the future, `afprintf` should be used for most multi-line debug traces.
moved foamPrintDb back into if-debug
moved abPrintDb back into if-debug