Icons for preview and terminal, add demoMode var

demoMode var now available to make use of in JS
New system DIV in footer along with 2 child divs which trigger new
functions to open the preview window or terminal
Get rid of nest display text, it's just clutter
system, preview, terminal & nest display changes

New class added for new system tools area below file manager, contains 2
child divs to display preview window and terminal icons
nesting class is now a small circle, placed near nestDisplay which
contains the breadcrumbs
nestDisplay class is moved along by 12px to accomodate the new smaller
nesting OK/broken indicator
Terminal moved to system & icon gone

Terminal is now no longer a plugin but part of the ICEcoder system. In
doing this, the icon was removed, plus the path to the settings.php file
altered
Jump to definition shortcut added

Shortcut re stickyTab now gone as we click icon to open preview window
now
Removed sticky tab shortcut, added live edits
All stickyTab refs now previewWindow
Icons for preview window and terminal added
Terminal plugin removed

Now part of the ICEcoder system
stickyTab now previewWindow
Working with previewWindow, plus new sys tools

stickyTab now previewWindow in all places
nestDisplay text now gone, was just clutter
nestValid and nestDisplay now move to be under editor when resizing file
manager
Now setting nesting OK/broken on title on new look nesting indicator
new functions for openPreviewWindow and openTerminal, tidied up code a
little
stickyTabMaybe now removed as a flag
Updated file