Consistent use of string methods

• use more standard forms of string access. Eg, substr() instead of the operator()(...) form, or even resize().
• turn off underscore prefixing by default for word::validated()
• new SubStrings container and associated stringOps::split operator. This container may also be useful for writing simple parsers.

changed the description

added code style enhancement labels

changed target branch from master to develop

changed milestone to %v1712

assigned to @andy

• just noticed, should probably have SubStrings instead of subStrings since it is templated. Fixing now.

added 2 commits

• b3ac6c3f - ENH: add Foam::SubStrings container and stringOps::split
• a2195d7e - ENH: allow '/' in ${...} blocks for future entry scoping (issue #429 (closed))

Compare with previous version

changed the description

assigned to @mark

mentioned in commit c2db86f0

merged