correction of derivative of acosh

git-svn-id: https://projects.coin-or.org/svn/ADOL-C/trunk@495 94ac48a7-3327-4b6a-8511-9a4036a20e83
Fix segfault in get_tay_block_r() after advanced branching

The keeping of the taylor was missing before we overwrote the result
for advanced branching operators, leading to a segfault in the
reverse mode

Signed-off-by: Kshitij Kulshreshtha <kshitij@math.upb.de>

git-svn-id: https://projects.coin-or.org/svn/ADOL-C/trunk@496 94ac48a7-3327-4b6a-8511-9a4036a20e83
Merge branch 'svn'
Merge branch 'master'(a042c40) into rev_hess

Conflicts:
	ADOL-C/src/adouble.cpp