hgcommand.vim: requirements & doc self-install more consistent; cosmetics
Check for availability of builtin system().
Set 'compatible' while sourcing script.
File operation during doc self-install:
Escape spaces in ex-commands.
Use quotes in system calls.
Incremented revision number(s).
Size of patch is due to cosmetic cleanups:
Removal of spaces at line endings.
<SID>Prefix to functions when called.
abort: impossible time zone offset: 4444444
transaction abort!
rollback completed
abort: invalid date: '1\t15.1'
transaction abort!
rollback completed
abort: invalid date: 'foo bar'
transaction abort!
rollback completed
abort: invalid date: ' 1 4444'
transaction abort!
rollback completed
abort: date exceeds 32 bits: 111111111111
transaction abort!
rollback completed
abort: No such file or directory: .../test/bar