Improved consistent drawing of box sizes between edit and display modes, adjusted positioning of text both in text and graph objects, provided consistent spacing on the left and right sides. TODO: work on auto-updating GOP gray rectangle when its size is adjusted through the sub-patch, as is the case with the 1.x branch.

fixed segfaults caused by preset_hub_read and preset_hub_readpreset (may want to revisit later to disable the crflag from the binbuf_read_via_canvas and consider implications of potentially running into an A_SEMI which currently does not appear to be likely, or dare I say, possible?)

This is needed to build when some dependencies are installed into
locations outside of /usr.

This brings us in line with the [build
API](https://github.com/cgwalters/build-api) used by flatpak-builder.

This reworks the file button in the help browser so that it opens the file
browser on whatever directory we visited last (as given by the current_dir
variable), or the doc directory by default.