Added an explicit instantiation of BoundaryOperator's binary plus operator.
Changed zdotc tests so that the exact result is not purely real.
Fixed compilation problems in AHMED-less mode.

Conflicts:

	lib/assembly/identity_operator.cpp
Updated to version 1.1.1 (with release notes added).
Added information on version 1.1.2.
Edited release notes.
Removed leftover debug messages.
Increased tolerances in test_inverse_sparse_boundary_operator.cpp.