Icon added for split pane controls
Lib added to establish text diffs
Pull actions to be added in v4.4 now
Split pane control classes added
results text moved, now used by JS file

Also reworded text re reloading so it relates to the diff pane
Diff and split updates

If the diff instance doesn't have focus either then we can go next/prev
tab
Load difflib.js file also
Split pane controls added, with split view being opacity 0.5
On setting GitHub diff to true, go split pane also
Implementing split pane

Tab lines now 0.15 opacity as a tweak
diff pane set to 50% width and add, remove and change diff classes added
cMOptions established as object to pass through when initialising editor
instances
Code related to initialising and adding actions to editor instance now
moved to main JS file and we are just about doubling everything up for
the diff pane
New events added for focus and blur also, with functions in main JS file
Active lines also created for diff pane
Handling split panes

Establish panes and which one we are looking at when running these
functions
Note: May need to not do this for switchMode, as the diff pane should
fall in line with the main pane
Handling split panes on file control

If GitHub diff mode, load the 2 JS files needed
Ask message shown needed escaped slashes so they appear OK in dialog
No longer open a new file for older version, we display now in diff pane
Temp code added in comment block re getting content from GitHub for file
to show in diff pane. This isn't working at present and probably just
needs a tweak to make work
Slightly renamed vars for active lines to handle 2 panes
Split pane, new functions and diff mode set up

New vars for splitPane, debounce and editorFocusInstance added
Split pane controls added and center themselves and can now trigger
single and split pane views
Editor functions added here for focus, blur, onkeyup, oncursoractivity,
onchange and oninputread, can handle requests from either main or diff
pane
updateDiffs function added which will show differences between 2 panes
using jsdifflib and markText
updatePreviewWindow now it's own function too
Many functions redone so they can also take requests from either main or
diff panes, by using thisCM instead of cM
getcMdiffInstance function also added
Diff pane also updated on changing settings and switching tab