tests/test-config-case.t

store: encode first period or space in filenames (issue1713)

- Mac OS X has problems with filenames starting with '._'
  (e.g. '.FOO' -> '._f_o_o' is now encoded as '~2e_f_o_o')

- Explorer of Windows Vista and Windows 7 strip leading spaces of
  path elements of filenames when copying trees

Above problems are avoided by encoding the first space (as '~20') or
period (as '~2e') of all path elements.

This introduces a new entry 'dotencode' in .hg/requires, that is,
a new repository filename layout (inside .hg/store).

Newly created repositories require 'dotencode' by default. Specifying

  [format]
  dotencode = False

in a config file will use the old format instead.

Prior Mercurial versions will abort with the message

   abort: requirement 'dotencode' not supported!

when trying to access a local repository that requires 'dotencode'.

New 'dotencode' repositories can be converted to the previous
repository format with

  hg --config format.dotencode=0 clone --pull repoA repoB

  $ echo '[Section]' >> $HGRCPATH
  $ echo 'KeY = Case Sensitive' >> $HGRCPATH
  $ echo 'key = lower case' >> $HGRCPATH

  $ hg showconfig Section
  Section.KeY=Case Sensitive
  Section.key=lower case