[Dillo-dev] dillo.cc cleanup and bugfix

I have split patch into three patches. geometry.diff fixes --geometry flag

Fixed --geometry flag. It is --geometry in man page but -geometry in usage and only -geometry is recognized by program.

getcmdoption.diff simplifies getCmdOption

Simplified getCmdOption. Removed State enum, it was overkill. It is also possible to remove support for mandatory arguments (opt_argc < 0) as it is not used, but it does not add LOC so I left it there.

aboutblank.diff removes unnecessary check.

Removed check for about:blank as start_page, it is not a special case.

Minor fixes (#include order, indentation) are not included.