CharBuf: renamed getter, added empty(), defaulted copy ctor and assignment operator.
test/text/escape: removed lonely apostrophe from output.
Tidy & doc tidy.
Token: added is_null(), empty(), size(), capacity ctor; defaulted copy ctor and assignment operator.
Variable: added stdlib front() and back() mimics.
VariableUtils: added numeric parsing to convert_typed().
ScriptParser: added support for named values within identifiers.
ScriptWriter: added IO::StreamContext ctor.
ScriptWriter: added support for named values within identifiers.
test/var: added tests for named values within identifiers and fail tests.
Variable: added at() and erase() stdlib mimics.
Args: new namespace; added parse_raw(), parse_cmd().