Demote warning to debug
Combine data from all ini-files in /etc/mce directory

This allows adaptation specific packages to override the
defaults specified within the mce source tree.
Make array lengths optional

Similarly to underlying g_key_file_xxx() functions.
Make evdev node classification configurable via ini files

The built-in defaults are still used if no configuration
is provided.
Async signal handling fixes

Do not try to pass non-recoverable signal handling to
happen in the mainloop context.

Unblock signals that need to be raised again to invoke
default behavior.

Substitute snprintf() and friends with async signal safe
helpers.
Merge pull request #20 from spiiroin/evdev_config

Input event device configuration can be specified via ini-files in /etc/mce