Fix UI text capitalization, edit text, and add screen shots.

Reviewed-by: con

The scanning phase was in some cases insanely long.
Reason was that Creator feeds wrong paths to the
CppModelManager, for example "/".

The scanning phase did what it was told to: scan that whole
Harddrive.

This patch makes sure that the scanning is not done for "/"

Done-With: Roberto

(The other Samba is meant. The slow one, not the nice one.)

Creator manages to feed the CppModelManager with all kinds of
wrong include paths. That is usually not a big issue as long
as that path is not a simple "/".

CppManager appended a separator to all incoming include paths.
And when the above "/" was passed in, we had (on my machine)
7 seconds of Samba Network lookup, multiple times during a
parse. And the sad thing was that my dear colleagues in the
Intranet did not even have the searched-for header files on
their shared folders.

This patch makes sure that a separator is only appended if
the path does not already end with one.

The real core of the issue (wrong include paths from Creator)
still needs to be fixed.

Done-with: Roberto Raggi

Reviewed-by: Christian Kamm

Task-number: QTCREATORBUG-2456

In some cases snippets have a description. Due to the sorting this
already places them after keywords. So this is just to be consistent
for all cases.

Task-number: QTCREATORBUG-1517

Task-number: QTCREATORBUG-2427

Introduce some more private classes for the coreplugin,
use header include convention
<QtModule/QClass>, de-qobjectify VariableManager.

Task-number: QTCREATORBUG-2307
Reviewed-by: Thorbjorn Lindeijer

There was a bug in 5cd6ebfd which meant
no reindent of the current line was triggered for the opening curly
brace on a new line.

Task-number: QTCREATORBUG-2331

Also introduce a indirection, modes have now types, edit and debug have
the same type, and editors do have a prefered type of modes instead of a
prefered mode.

That fixes the bug that if the prefered qml editing mode was set to
design, then in switching between qml editors would
- in Edit Mode: stay in edit mode
- in Debug Mode: switch to debug mode

Task-number: QTCREATORBUG-2300

This should make the indenter less strict and annoying for non-standard
indentation styles.

Reviewed-by: Roberto Raggi

Thanks to this patch we can move the filtering of C++ symbols
in a background thread.

Done-with: Erik Verbruggen

The function always switched to Edit Mode, which was the cause for
several bugs. Since openEditor() already does switch to the right mode,
the function is not really needed.

The following actions now respect the prefered mode of the editor:
"f file"-locator
The Open Documents list
Editor history navigation

Task-Nr: QTCREATORBUG-2243

Task-number: QTCREATORBUG-2111

This makes sure styles are consistent for the editor and the quick fix
engine.