grep: extend functionality, add man page entry, add unit test.
walkchangerevs now returns a two-tuple. Its behaviour is also
extensively commented.
The annotate command's getname function has been factored out to a new
function, trimname, so it can be shared between annotate and grep.
The behaviour of grep has been beefed up, so that it now performs a
number of useful functions.
#!/bin/sh
mkdir t
cd t
hg init
echo This is file a1 > a
hg add a
hg commit -m "commit #0" -d "0 0"
echo This is file b1 > b
hg add b
hg commit -m "commit #1" -d "0 0"
rm b
hg update 0
echo This is file b2 > b
hg add b
hg commit -m "commit #2" -d "0 0"
cd ..; /bin/rm -rf t
mkdir t
cd t
hg init
echo This is file a1 > a
hg add a
hg commit -m "commit #0" -d "0 0"
echo This is file b1 > b
hg add b
hg commit -m "commit #1" -d "0 0"
rm b
hg update 0
echo This is file b2 > b
hg commit -A -m "commit #2" -d "0 0"
cd ..; /bin/rm -rf t
mkdir t
cd t
hg init
echo This is file a1 > a
hg add a
hg commit -m "commit #0" -d "0 0"
echo This is file b1 > b
hg add b
hg commit -m "commit #1" -d "0 0"
rm b
hg remove b
hg update 0
echo This is file b2 > b
hg commit -A -m "commit #2" -d "0 0"
cd ..; /bin/rm -rf t