Updating build script.

* Now relies less on conditional compilation, instead options for
compiling Mond are specified on the command line which is passed to the
compiled .exe at runtime.
* Supports both static libs and shared libs.
* Now uses absolute paths.
* Write command line arguments that are to be passed to the compiler to
a temporary file first in order to avoid "command line too long" errors.
* Explicitly specify that phobos.lib should be linked to the binary.
* Includes help switch to print usage to the user.
* Replace tabs with spaces.