zsh bc: avoid the '~' parameter expansion flag
zsh bc: avoid the '~' parameter expansion flag

zshexpn(1) from a newer zsh version:

   ~  Strings inserted into the expansion by any of the flags below
      are to be treated as patterns.  This applies to the string
      arguments of flags that follow ~ within the same set of
      parentheses.  Compare with ~ outside parentheses, which forces
      the entire substituted string to be treated as a pattern.
      Hence, for example,

        [[ "?" = ${(~j.|.)array} ]]

      treats `|' as a pattern and succeeds if and only if $array
      contains the string `?' as an element.  The ~ may be repeated
      to toggle the behaviour; its effect only lasts to the end of
      the parenthesised group.

zsh-4.3.6 (SLE-11-SP3) does not have this (4.3.10 in RHEL-6 is fine).

luckily, $to_html keys are not pattern metacharacters so i can just
treat the whole thing as a pattern and be done with it.

roman-neuhauser/git-grope,roman-neuhauser/git-grope,roman-neuhauser/git-grope