Add comment about assertions and reorganize the code a bit.
* src/fileio.cc (save_iochannel): Add comment about assertions and reorganize the code a bit. (Regexxer::save_file): Elaborate on why IOChannel::close() is used explicitely. * src/filetreeprivate.cc (FileTreePrivate::collatekey_sort_func): Fix oversight: Subtracting two unsigned values and converting the result to a signed type relies on implementation-defined behavior. Explicitely cast the operands to a signed type before substraction. * src/main.cc (main): Use g_get_prgname() instead of the string literal PACKAGE_TARNAME in the error message for Glib::OptionError exceptions. svn path=/trunk/; revision=621