pickconfig: ignore nonexisting dirs in CONFIG_DIR

Makefile.inc.in includes:
    /usr/local/etc/emc2/configs
in:
    EMC2_SYSTEM_CONFIG_DIR
but the directory doesnt exist and is not created
so: don't show nonexisting dirs
rearrange: provide gladevcp-test.ui

link outside root/configs will not work with deb install
pickconfig: deeper search for ini files

a subdir will not be copied to user configs if it or
any children contain ini files since such a directory
will be considered a potential config and included
in picker tree