Fix issue when focused_context is greater than 0x7FFF

Fix issue when focused_context is greater than 0x7FFF

Since opensource SCIM generates helper_ic using the formula
helper_ic = (uint32)(client&0xFFFF)|((context&0x7FFF)<<16);
, if the context is greater than 0x7FFF the operator "="
is not appropriate for comparing two contexts properly.
Thus added compare function for contexts and modified to use
focused_context variable that is not being truncated by the
helper_ic generation formula.
But still, helper_ic related code seems to need a refinement.

Change-Id: Iecf2c72788b7d3acebb4b119ad0fe4ea78a6b881