cleanup iemgui dialog form names, replacing dashes with underscores. Fix stray bugs in canvas dialog, and clean up css selector names

fix "stale pointer" bug when re-opening a subpatch on a scalar that has an event bound to it. The bug was that the scalar symbol wasn't getting unbound because scalar_vis wasn't getting called.

fix #119: store canvas title for later use. This will properly display the title for a dirty canvas in the case where the Pd patch is mutated with a loadbang (and properly other cases, too)

These bugs were discovered via static code-analysis
https://scan.coverity.com/projects/pure-data-pure-data
(The CID numbers are the "Coverity IDs" used to identify the various bugs)

- Don't free binbuf within glist_readfrombinbuf (CID:74871)
- it must be deleted by the caller
- Initialize sockaddr_in (CID:74861,74862,74863,74866)
- Initialize indelay/outdelay (CID:74864,74865)
- Initialize device-arrays (CID:74853,74854,74855,74856)
- Closing unneeded sockets (CID:74827)
- Initialize sockaddr_in (CID:74860}
- Close file-descriptor if the soundfile is unparsable (CID:74822,74823)
- Close file-handle in cleanup (CID:74816)
- Call va_end() when handling variadic args (CID:74872)
- Added missing break (CID:74800)
- Prevent NULL-dereferences (CID:74792,74793)
- Size checks when copying into string buffers (CID:74844,74845,74846,74847,74849)
- Freeing no-more used storage (CID:74832)
- Fixed code block (CID:74806)
- Initialize sockaddr_in (CID:74860)
- Initialize array-values to 0 (CID:74867)
- Free allocated memory (CID:74813,74830)
- Removed allocation of unused memory
- Use pd_free() to free templates (CID:74814)
- template_free() does not free the entire structure (it misses the pd_new() part)
- initialize variable (CID:77865)
- Prevent NULL-pointer dererencing (CID:77864)
- Free heap-allocate binbuf after use (CID:74833)

port a031e3b64f725c8cb3274b5ef3ff0e27a36222f5 from Pd-l2ork: fixed parsing of @pd_extra and @pd_help names in filenames

port 9ab1b10476bca7e3998d5bf907296979dfc6e558 from Pd-l2ork: fixed regression where canvaslist was not properly stored

port e814c4d586c52fe9a6a39a58947df1870e04e986 from Pd-l2ork: updated load/init/closebang to match the new spec

*Reverted http://sourceforge.net/p/pure-data/pure-data/ci/97851b3c44b2b3839069928d90ca6185de4455c5/ as it disables ability to address abstractions via scripting (needs further testing to figure out why was this disabled in the first place and then later reverted by Miller)
*fixed way of vis-ing GOP-enabled abstractions via script

fix regression with [pd] not respecting new box dimensions when renaming to [pd foo]. Also, comment out more sys_vgui calls in g_canvas.c

fix iemguis and canvas scalehandle to track mouse position instead of delta-- this fixes a bug when the mouse goes below the minimum dimensions. Plus, some more cleanup of the scalehandle code

add boilerplate for keeping track of toplevel Pd canvases in the GUI. While the GUI knows all the open windows, it can't tell the difference between a Pd toplevel and a subpatch. I'm not sure why the difference is important, but this interface supplies that info to the GUI.

further refined legacy mode to match both iemgui and graph-on-parent objects.

second draft of iemgui handles--- still some bugs when switching between canvas gop rect and iemguis