#488 check command and libanalyze function to do the work of rtcheck

[Sharan]

This is a check command that uses a newly implemented libanalyze function - analyze_overlaps.
The check command does what rtcheck does but uses a function instead of the current implementation that uses an executable version of rtcheck.
The libanalyze function takes a callback function and callback data, that is used to fill up the local overlap list of ged_check with overlaps using a local function (add_overlaps).
This function is called by a adapter which has the same prototype as a_overlap expects.

[Sharan]

Describing the two patches:
1) check_bu_exit.patch - this has everything as it is with bu_exit for any errors that occur, I found that a bit harsh for MGED to exit for something like a typo when giving the command so I made a new patch with using return and making all the functions int type instead of void, then evaluating these return values.
2) check_return.patch - As described above, also I noticed that rpt_overlaps feature was not working so I removed the -r option because the existing rtcheck sets a_logoverlap to rt_silent_logoverlap in view_init making the -r option redundant. (The first patch doesn't have this removed)

[Daniel Roßberg]

OK, stay with the check_return.patch.
- Most important, I would like to see the object selection in ged_check().
- Next important, using application.a_overlap is deprecated. See include/rt/application.h.
- I would give the add_overlaps parameter of analyze_overlaps() in include/analyze.h a different, more general, name. For example simply "callback" or "overlapHandler". It should signal the user that they can implement anything here, not just adding the overlap to a list.
Otherwise, it looks good, I would say.

[Sharan]

Following changes:
1) Moved object selection to libged.
2) Moved do_ae and grid_setup to libged, resulting in a smaller parameter list for libanalyze :)
3) Changed overlapsAdapter to the match a_multioverlap defintion.
4) Renamed add_overlaps in analyze.h to callback.

[Sharan]

Following changes:
1) Using a_logoverlap instead of a_multioverlap for passing the overlapsAdapter.
2) Doing processing in libged only.
3) Renamed command to check_overlaps.
4) Renamed files, libged/check.c to libged/check_overlaps.c and libanalyze/overlaps/check_overlaps.c to libanalyze/overlaps/analyze_overlaps.c

[Daniel Roßberg]

To speed it up I accepted your patch, but it has some minor issues:
In include/analyze.h:
- newline at line 128
- name the parameters in analyze_overlaps_callback, such that the user hasn't to guess what they mean

In src/libanalyze/overlaps/analyze_overlaps.c:
- remove spaces in line 326

In src/libtclcad/tclcad_obj.c:
- use a tab

Test with Archer.

Please, correct them with an own patch.