QCOM LPG LEDs expose a hw_pattern sysfs entry which accepts a limited
set of patterns but allows to use dedicated hardware for blinking the
LED. This way, battery life can be improved and the LED still blinks,
even if the device is suspended.
Themes (other than the default theme) can specify a `parent-name` in the
json file. This theme will be used as a base for the theme. Events and
profiles of the children override those in the parents.
For this we move the lookup code into it's separate class and also add
tests.
Closes: #38
Dylan Van Assche
Guido Günther