The part responsible for generating a mapping between the shell/ions
and block projector matrices has now been relocated to a separate
method 'get_block_matrix_map()'. This simplifies the source code
and makes testing easier.
The mapping for NORMION = True has been implemented.
Also, the orthogonalization loop has been fixed. First of all,
orthogonalization should be done separately for each block map 'bl_map'.
Second, one has to take into account that the orbital dimensions of the
block matrix can vary from block to block. To make that the overlap
matrix is non-singular one, thus, has to pass to
'orthogonalize_projector_matrix()' only a view of a submatrix of 'pmat'
corresponding to the current block.
Two tests to check the simplest cases have been added.
The implementation of the mapping of a set of projectors (belonging
to different shells and ions) onto a block matrix in the
orthogonalization routine has been generalized. Now, an implementation
of the choice between the full orthogoanlization and per-site one
is straightforward: it is just a matter of defining a proper mapping.
The mapping scheme itself is described in the doc-string of method
'ProjectorGroup.orthogonalize()'
There was a very nasty bug in the preparation of the block matrix
'p_mat'. The point is that this matrix is created once for all k-points
with the band dimension being the maximum possible. However, only
a part of the matrix is used at every k-point but the orthogonalization
is done for the whole matrix. The problem was that if the number of
bands for a given k-point was smaller than that for the next k-point
them for the next k-point some part of 'p_mat' still contained data from
the previous step, which messed up the orthonormalization. Now, 'p_mat'
is set to zero at each step of the loop.
Also, property 'nion' was added to ProjectorShell since it is used
very often.
Added missing import of ProjectorGroup and ProjectorShell to
'plotools.py'.
Moved separate routines 'orthogonalize_projector_matrix()'
and 'select_bands()' into class ProjectorGroup because these
routines are anyway not used elsewhere outside this class.
The classes ProjectorShell and ProjectorGroup are now defined in
different source files. This makes 'plotools.py' only contain
routines that control the data flows, including consistency checks
and output.
