pickconfig: reorder dir display for preferred

1) reorder display of directories to show preferred items first
2) change openmode to simplify first view
   but go to last_ini if available
3) display text when selecting top nodes too
4) add some notes
configs: rearrange configs

v2
configs tree:
   sim----------------goal is for configs that run
                      without i/o hardware requirements
                      for:
                          demonstrating features
                          displaying/testing gcode
                          teaching configs by example
                          testing linuxcnc code
   by_interface-------parport,pico,mesa,...,
   by_machine---------sherline,smith,tormach,...
   attic--------------for study,history,etc
                      currently: only demo_mazak as an example

-------------------------------------------------------------------
When adding or moving config subdirectories, the src/Makefile
should be reviewed for changes needed for COPY_CONFIGS.  If an ini
file is moved to a different depth in the tree, the settings
for PROGRAM_PREFIX,SUBROUTINE_PATH,USER_M_PATH etc should be
updated for testing with rip builds.

Note: any config directory can (should?) include a README and each
individual ini file may be (optionally) documented with a .txt file
with the same basename.  Many existing files need updating for
accuracy and completeness.
-------------------------------------------------------------------
Notes:
   edited sim ini files for PROGRAM_PREFIX=../.. stuff
   (this is only needed for rip builds since pickconfig
   supersedes it)
   i also edited for SUBROUTINE_PATH= and USER_M_PATH=
   but may have missed some (also mainly for rip)
-------------------------------------------------------------------
Testing:
Some configs are probably broken but it is necessary to check
if a failing config was working before this commit

i tried all sim configs to see if they startup, some notes:

python_demo/axis_noio.ini  works, but it takes a while to start
                           maybe that is normal

these fail (but fail in git-master for me before this commit):
python_demo/owordm6-ui.ini fails -- some gtk message
                           (owordm6-ui-ns.ini does start)

python_demo/py.ini fails:
                    Pin 'iocontrol.0.user-enable-out' does not exist
                    waiting for s.axes
python_demo/py.iocontrol  fails: several errors reported
rearrange: relocate subdirs to parents

mv ngcgui files using axis   to the axis subdir
mv ngcgui files using touchy to the touchy subdir
rearrange: fix links for gladevcp-test.ui occurrences
rearrange: mv more subdirs to parent

halui_pyvcp    to axis
simtcl         to axis

gscreen_custom to gscreen
rearrange: gladevcp distribute to subdirs

gladevcp ini files in assets that comprise runnable linuxcnc
sims moved to appropriate subdir of a parent dir

the gladevcp_base dir moved to root (comparable to
root/scripts,root/tcl etc).  Examples therein are
runnable gladevcp apps (not requiring linuxcnc)

this leaves root/config as linuxcnc-configs only
pickconfig: preferred names on sample configs only
rearrange: mv more subdirs to axis

python_demo and remap
rearrange: mv vismach to axis

hexapod-sim/minitetra.ini changed to use:
   [DISPLAY]DISPLAY=axis
for consistency with other configs in vismach dir
rearrange: mv pyngcgui gscreen files to gscreen
pickconfig: show files before directories
rearrange: make links in sim consistent
rearrange: mv gmoccapy ngcgui examples to subdir
rearrange: make simlinks consistent
pickconfig: follow nested symlinks correctly

also: clarify env for debug_pickconfig
configs: mv general_mechatronics to by_interface
pickconfig: provide default_start_node

if no ~/.linuxcncrc, go to hardcoded default_start_node
pickconfig: allow window resize
docs: fix Spanish master doc to use translated docs
docs: rebrand some page names