corrected the shebangs of inlineparser.rb and blockparser.rb
the first commit of plaintextformat.rb
use PlainTextFormat#format instead of PlainTextFormat.format
introduced TC_PlainTextFormat#setup
added TC_PlainTextFormat#test_heading
added verbose_mode of LinkNodeFormatter
implemented DescLeafFormatter#visit
added TC_PlainTextFormat#test_table
added PlainTextFormat::TableCell and PlainTextFormat::TableSep
corrected a typo
Merge branch 'develop' into plain-text-visitor
added TC_PlainTextFormat#test_verbose_mode_table
implemented TableLeafFormatter and TableNodeFormatter