Added support for TYPEs

(and fixed a potential bug with empty arguments.)
Made TYPE opaque.

It didn't make sense to parse it separately: too many edge cases and too
little information.
Recognize symbols in the form @NUMBER.
Support for EQUIVALENCE statements.
Finally made the symtable entry attributes flexible.
The parser stores the range of things.

(start line&col and end line&col)
Remove unused TOK_NUMBER
Made the scanner not use REJECT.

This makes the scanner able to parse HUGE tokens (>16k), which DO happen.
Sync with master of flex-bison-indent.

Fixes multiple simultaneous outdents on non-0 column.
Dramatically simplified label parsing logic.

And added a big ass comment with examples.
Finally correct parsing of ELSE and ELSE IF blocks.
Fix compilation error when %debug is off.
Fixed the case of RETURN and ELSE on the same line.
Added a workaround-ish rule for wrong indentation.

It's an ugly hack but at least provides diagnostic on stderr.
Clean output. Json->stdout, errors->stderr.
Some test cases I should've commited long ago