mergetools: add alternate registry keys for 32bit apps on 64bit O/S
Not all applications needed the workarounds, so I did not add alternate keys for
every Windows merge application.
filemerge: introduce a 'regkeyalt' merge tool variable
This allows us to provide alternate search keys for 64bit operating systems that
may have 32bit merge tools installed. Presumably it may find other uses.
zsh completion: remove computed default values from help texts
The default encoding and encoding mode are computed at runtime and can
vary from system to system. The two remaining default values in the
completion help texts (number of directories to strip on import and
default bundle name) are fixed in the source code.
merge: remove last traces of fastforward merging
bbc97d419b16 introduced fast-forward branch merging.
66ed92ed115a partly removed it again.
The fastforward variable would always be false if branchmerge was false, so the
fastforward variable makes no difference and we can remove it completely.
subrepo: backout
67fbe566eff1, --force requires svn >= 1.5