Use mce-plugin-libhybris for proximity sensor input

If mce-plugin-libhybris is installed and support for proximity
sensor is available, the mce proximity plugin will utilize it.

[mce] Support proximity sensor via mce-plugin-libhybris
Use mce-plugin-libhybris for ambient light sensor input

If mce-plugin-libhybris is installed and support for ambient light sensor
is available, the mce filter-brightness-als plugin will utilize it.

[mce] Support ambient light sensor via mce-plugin-libhybris
Do not resolve mce-plugin-libhybris symbols from mce binary

The mce-plugin-libhybris DSO and mce executable have common
dynamic symbol names by design, but references from the plugin
side must not be resolved to mce side functions.
Do not count ALS and PS input event sources as user activity

Since mce does not have functionality for directly handling
evdev based ALS / PS events, they must be excluded from
user activity tracking list. Otherwise enabling the sensors
via libhybris might cause a situation where inactivity timeouts
never trigger due to sensor noise.
Updated header file dependecies
Merge pull request #49 from spiiroin/sensors_via_libhybris

Use proximity and ambient light sensors via libhybris