improved error context handling, removed error_printf.
make get_str() skip spaces before and after token.
simplified use of get_str(), removing space skipping.
simplified libqhtml/xmlparse.c and libqhtml/cssparse.c accordingly.
extend config file syntax :
support for 1 level if(0 or 1) { } blocks
report syntax errors
added local config files .qerc for project based settings
added TODOs
added support for home dir syntax in canonize_absolute_path().
