Improve String#eql?

String#eql? is not alias of String#==.
Fix "Z" in pack-template
Set reference version 2.0.0
Add caution for 2.0.0
Ignore Gemfile.lock
Merge pull request #7 from sanemat/fix/gitignore

Ignore Gemfile.lock
Merge pull request #6 from sanemat/feature/ruby-version

Add 2.0.0 texts
svn -> Git
Update REXML::Document
Update REXML::XMLDecl
Update REXML::Comment
Update REXML::XMLDecl
Remove internal encoding classes (and the classes are removed after 1.9) in rexml:
Remove an old config file
Add version guard for Time.{gm|utc} with a special year
Add version guard for Time.{local|mktime} with a special year
Add a variety of arguments on Time.new

except `utc_offset` is a `:std` or `:dst`
Merge pull request #9 from kachick/time-new-arguments

Time.new with arguments
Fix Time.new parameter description
Merge pull request #8 from kachick/fix-time-cunstructors_with_special_year

Add version guard for Time.{gm|utc|mktime|local} with a special year

Since 1.9.1, 0..38 is 0..38 not 2000..2038.