Issue 112

as per the discussion in issue #112, I have added the large font size and text anti-aliasing settings to the application settings dialog. I changed the way this is handled by `ViewPainter::init()` as it now checks itself the `QucsSettings`, instead of having to pass explicit parameters (since we will pass all the time fixed parameters corresponding to the `QucsSettings` content).
I could not resist and fixed also a few typos and upper/lower case initials stuff to have a more uniform name/description.
Thinking about it, having also a separate selection for the text anti-aliasing might not be that helpful, we might leave it always enabled, also because it seems to be enabled by default and just clearing the `QPainter::TextAntialiasing` flag does not necessarily disable it (should be done on `QFont`, see http://qt-project.org/doc/qt-4.8/qpainter.html#rendering-quality ).
I wanted to add some more comments in the files but did not have time...

On an unrelated note, I had also to modify the main `configure.ac`, as I have recently installed the Qt3 libraries in parallel with Qt4 (to work on issue #91) and discovered that Slackware uses `QT4DIR` for the location of Qt4, if Qt3 is also installed (`QTDIR` now points to Qt3). For handling this I had to move a couple of things around in the file, please check if this works for you.
Note that `CMake` still works perfectly, its Qt detection routines work much better...