added  a new option --split-main-heading
Merge branch 'develop' into 2html
Merge branch 'develop' into 2html before the correction of pseudohiki2html.rb
use ARGF.readlines() instead of obsolete ARGF.lines()[.to_a]
correct the help message of pseudohiki2html.rb
refactoring TableRowParser#treated_as_node_end()
refactoring TableRowParser#push()
InputManager#create_table_of_contents returns if OPTIONS[:toc] is not set
a tidy-up of TreeStack
introduced BlockParser#in_link_tag?() and use it in #tagfy_link()
add --split-main-heading option
option --split-main-heading can be used without template