Complete quoting for parameters of some CMake commands.

[A wiki article pointed out](http://cmake.org/Wiki/CMake/Language_Syntax#CMake_splits_arguments_unless_you_use_quotation_marks_or_escapes. "CMake splits arguments unless you use quotation marks or escapes.") that whitespace will only be preserved for parameters in CMake commands if passed strings will be appropriately quoted or escaped.

Quoting can be added so that more places should also handle file names correctly which contain semicolons eventually.
No worries. This version number doesn't really matter that much; it's updated more conscientiously in the [release branches](https://github.com/sqlitebrowser/sqlitebrowser/blob/sqlb-3.2.x/CMakeLists.txt#L109). I think it would make most sense to replace it by some '999' dummy version number, just like it's done when the .git directory is found.