remove install-icon rule from install rule, because there's already another icon & desktop file in packages/linux_make/

* disabled warnings about unused parameters (which are pointless) & enabled warnings about other unused local variables (which allow to find dead code)

*code clean-up
*brought the rest of disabled tcl files up-to-date with the 0.45 branch for possible future merge

*enabled drag'n'drop in the main window/console, as well as patches
*implemented properly supported horizontal touchpad scroll (in addition to vertical and shift+vertical, which is being handled as horizontal)
*pd-gui fails to start (missing pd-l2ork in the $lib/bin/ directory)

*fixed drawsymbol scalars' double names
*improved build process for tkpath
*improved to-front/back logic

Protection against closing dirty abstractions
closing and quitting doesn't query if everyone is clean
(but "pd perf" message turns that protection back on for performances)
ctrl-1, etc, automatically place new object under a selected one and
connect to it
return when editing an object (not a message or comment) deactivates text