Updated C-/N-terminal partial charges in Amber03.ff.

At the time of porting the AmberFFs were validated against
AMBER 8 and the results have matched precisely. However,
that specific AMBER version had a bug due to which CT/NT charges in ff03
were in fact using ff94 charges. The bug correspondingly propagated
to the Gromacs ports. In newer versions of AMBER this has been fixed.

The current GROMACS patch uses charges as specified in the
all_aminoct03.lib and all_aminont03.lib files as
taken from the AmberTools14 distribution. 

In that distribution (14) seem to be no updates to the ff9x parameters. 

Fixes #1466.

Change-Id: Ie6cfea5702500ff6cd5019edb22f224d29135425