fixed segfault regression in 4.datatructures/05.array.pd example where clicking on the scalar array in a subpatch would cause a segfault

*experimental: disabled flow control as per http://article.gmane.org/gmane.comp.multimedia.puredata.general/24447

made mouse click logic ignore comments at runtime to allow clicks to be sent to proper objects that may be under the comments

*fixed bug where with JOC enabled in subpatch this only works for the bbox of the array, not the entire window
*made intelligent offset to various forms of array representations so that scrubbing with mouse accurately applies to closest points
*disabled drawing of a GOP rectangle inside GOP array window
*disabled ability to insert objects inside a subpatch with an array

added Jonathan's revision of the array properties and options with fixed font sizes and other minor fixes. LINGERING PROBLEM: array does not redraw (only after apply does it re-appear). Likely shouldvis problem.

*fixed improper paste location for scalars due to incorrect casting of t_scalar to t_text to retrieve its x and y positions

*fixed incorrect getrect when selecting a plot with scalars at each point (see setsize-help.pd). This was a regression from an earlier "fix" (see https://github.com/pd-l2ork/pd/commit/f0916f85a11894a43067d5b07ae5f8eea2b2c1b9#diff-5ff2b78bd60b3b9c36db43b8d5f5c168). The latest code does not exhibit the said problem so this should be all ok.
*fixed embedded scalars at each plot point not being selected for displacement with tag due to clumsy way of labeling them. This is achieved by adding scalar arg to the parentvisfn which also alters g_canvas.h spec but also makes things more streamlined.

*Ported open_via_helppath from pd to fix inability to open help files when starting pd-l2ork from the doc/5.reference folder.

cleaned-up gpio external dependencies and supporting build script. made disis_gpio external into a comprehensive object for all things gpio, including pwm (both hardware and software) with sarcduino-like formatting and verbose output. The external requires sudo due to required access to /dev/mem and /sys/class/gpio

*forced array graphs to keep GOP/hidetext under all circumstances (later update properties window so that the GUI reflects this rather than printing info in the console)

*removed unnecessary logic for keeping carriage returns to avoid having an empty line at the top of the console after clearing console

*forced hidetext on all gop arrays to make its resizing sane. Later update properties to reflect lack of this option.

*fixed segfault when trying to create an object inside an array GOP due to incorrect check whether the object is an array in shouldvis function that is being called as part of gobj_vis to optimize (re)drawing

*made GOP aware of minimum size when having an array embedded inside it

added ability for comments to be navigated by rows (using up/down), as opposed to home/end which takes you to the beginning/end, or ctrl+left/right which takes you to the next space

backported comment resize marker, updated it to support pd-l2ork and selection colors, added fix to the resizable objects to support abstractions and subcanvases.