Speedup and cleanup of exact-exchange part, courtesy of Marco Govoni


git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@11112 c92efa57-630b-4861-b058-cf58834340f0
Allocate qb with correct size nhm (instead of nkb, which can lead to unnecessary massive memory usage).
Added clocks to the most commonly used subsroutines and clock printout.
Small stylistic changes to stdout format.
-GS


git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@11113 c92efa57-630b-4861-b058-cf58834340f0