Add future for parsing boolean config args that include a space delimited value.

This does not parse correctly:

  ./configVarBooleanSpaceAfter --x true

These forms do work for booleans:

  ./configVarBooleanSpaceAfter --x=true
  ./configVarBooleanSpaceAfter --x

The space delimited form does work for other types that do not support the
implicit value (--<var name> is a special case for booleans).
Merge branch 'master' of github.com:chapel-lang/chapel into future-for-bool-config-arg-parsing
Merge pull request #131 from thomasvandoren/future-for-bool-config-arg-parsing

Add future for parsing boolean config args that include a space delimited value.

This does not parse correctly:

```bash
./configVarBooleanSpaceAfter --x true
```

These forms do work for booleans:

```bash
./configVarBooleanSpaceAfter --x=true
./configVarBooleanSpaceAfter --x
```

The space delimited form does work for other types that do not support the implicit value (`--<var name>` is a special case for booleans).