Links with unbalanced parentheses cause an exception

[tomyeh]

[foo](link(1.png) (what?)

00:00 +29 -1: original/inline_links.unit line 80: links with unbalanced parenthesis [E]
  RangeError (index): Invalid value: Not in range 0..24, inclusive: 25
  dart:core/runtime/libstring_patch.dart 931:55    String.codeUnitAt
  package:markdown/src/inline_parser.dart 118:35   InlineParser.charAt
  package:markdown/src/inline_parser.dart 899:39   LinkSyntax._parseInlineBareDestinationLink
  package:markdown/src/inline_parser.dart 803:14   LinkSyntax._parseInlineLink
  package:markdown/src/inline_parser.dart 638:24   LinkSyntax.onMatchEnd
  package:markdown/src/inline_parser.dart 1191:16  TagState.close
  package:markdown/src/inline_parser.dart 1130:7   TagState.tryMatch
  package:markdown/src/inline_parser.dart 104:57   InlineParser.parse.<fn>
  dart:_internal/iterable.dart 89:15               ListIterable.any
  package:markdown/src/inline_parser.dart 104:12   InlineParser.parse