util._hgexecutable: default to 'hg'
This should make hooks work even if util.set_hgexecutable is not called
(e.g. hgweb.cgi).
Fixes issue625.
adding he
llo
abort: '\n' and '\r' disallowed in filenames
adding he
llo
abort: '\n' and '\r' disallowed in filenames
adding hell
o
abort: '\n' and '\r' disallowed in filenames
adding hell
o
abort: '\n' and '\r' disallowed in filenames
f he
llo he
llo
f hell
o hell
o