Merge pull request #304 from jankoboehm/spielwiese

Added example where std over transcendental extension takes very long
removed libpolys/polys/OBSOLETE_pInitContent.cc
fix: n may be divisible by 2^...: not a bug(n==0) in this case
fix: avoid spurious messages in debug output (unless debugging mpr stuff)
fix: better error tests for alg.ext.
fix: ensure float_len2 >= float_len
fix: better constructors for float stuff
fix: assumption wrong
fix: float_len2 is the additional, invisible accuracy
fix: for PLURAL: len(p) != len(m*p)
fix: normalization for trans. ext.
chg: opt. (not computing log(l1) if l1 is unchanged)
fix: unify changes for HAVE_RING and HAVE_PLURAL
fixes for the static version
chg: removed SI_THREADS (unsed code)
Fixed broken BS and silenced a failing test (ClearDenom != cleardenom)
Fixing BS
Updating the BS + search pathes for better binary distribution (due to Hans)
chg: removed switching off of switches
chg: updating doc, p1