Do not reject all of memnotify input if unknown data is found from it

Adding new memnotify values makes mce ignore even the values it is
expecting to see.

Make mce skip unknown values and only warn about possible out of
sequence values.

[mce] Do not reject all of memnotify input if unknown data is found from it. Fixes JB#24908
Allow user processes to query current memory level over D-Bus

The get_memory_level method call was missing from mce dbus configuration
file and thus non-root processes could not query the current state.

Add dbus config entry for the get_memory_level method call and allow
non-root processes to make the query.

[mce] Allow user processes to query current memory level over D-Bus. Fixes JB#24382
Merge pull request #228 from spiiroin/jb24908_memnotify_parser

Do not reject all of memnotify input if unknown data is found from it
Merge pull request #229 from spiiroin/jb24382_memnotify_dbus_query

Allow user processes to query current memory level over D-Bus
Bump mce version to 1.38.1