Squashed 'sglib/' changes from 0ec7b66..b4b5d18

b4b5d18 Removed math utilities from util to mathutil
6f2db34 Added and updated almost all Contents.m files
5fe89bd added pushdirect option to sglib-subtree
1701380 Update unittest for compute_pce_matrix (better coverage)
d011745 Huge cleanup and moving into packages sfem and pce.
df15bfb Changed funcall unittest to be independent of current format options.

git-subtree-dir: sglib
git-subtree-split: b4b5d187ac2a1300871e9641cd846ec7439c03c3
Merge commit '4f35925a791c2e983f489c59b8dc87fdc7966f42'
Fixed the build_multiindex script
Added an error message to multiindex...

...if the old version of the interface is used