Fixes: - react on build/ run configuration changes
       - now notices environment changes, like switching Qt versions
       - start button is now only shown if we have a valid qemu runtime
       - enabled/ disabled state works properly when loading a project

Task-number: QTCREATOR-210, QTCREATORBUG-1252, QTCREATORBUG-1082
Reviewed-by: ck

Reviewed-by: kh1

Reviewed-by: kh1

Reviewed-by: kh1

Reviewed-by: kh1

Reviewed-by: kh1

And refuse to add it twice. The check is pretty simplistic in that it
doesn't take scopes or which variable it's exactly in into account.
But in those cases you need to edit the .pro file manually anyway.

Task-Nr: QTCREATORBUG-932
Task-Nr: QTCREATORBUG-891
Task-Nr: QTCREATORBUG-653

That is e.g. SOURCES instead of whatever variable is used first in the
project file.

Reviewed-By: ossi

Fixes broken enabled/ disabled qemu start button behavior.

Task-Nr: QTCREATORBUG-765

Quick fix by copying code also found in Qt4 and QML project managers.
Would be better to have some common solution...

Task-number: QTCREATORBUG-1383

Reviewed-by: ossi

Reviewed-by: Leena Miettinen

The symbian makefile generator don't support shadow builds. Thus they
always pollute the source directory with build artefacts. Mixing
in-source and shadow builds is obviously broken.

We do as good as we can, setting OBJECTS_DIR, MOC_DIR, UI_DIR, RCC_DIR
to .obj, .moc, .ui and .rcc, which keeps the source dir clean of at least
some of the artefacts. This is as good as we can, but not really good.

Task-Nr: QTCREATORBUG-1293
(cherry picked from commit 33ef722b)

Symbian mkspec puts the package file into the build directory,
not the destination directory.

Task-number: QTCREATORBUG-1341

 ... as default whenever that is selected

We already have it in the projects mode so we might as well
use the same in "Getting Started".

Reviewed-by: danimo

By popular request I added a "open project" option.
We don't currently have a way of differentiating project types
from other files so I had to hardcode .pro and .qmlproject
for now.

Themed icons was also added to the new and open buttons.

Reviewed-by: danimo
Task-number: QTCREATORBUG-1142

Reviewed-By: Jens Bache-Wiig

The Parentheses, TextBlockUserData and TextEditDocumentLayout classes
and their member function implementations were spread around the
BaseTextEditor class. Moving them to their own file to make the code a
bit better organized.

Reviewed-by: mae