ext_conf_builder.rb: remove circular dependency in install-so

* lib/rubygems/ext/ext_conf_builder.rb
  (Gem::Ext::ExtConfBuilder.hack_for_obsolete_style_gems): remove
  circular dependencies in install-so too.  [ruby-core:52882]
  [Bug #7698]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39572 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
mkmf.rb: libpath_env

* lib/mkmf.rb (MakeMakefile#libpath_env): set runtime library path for
  the case rpath is disabled.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39573 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
mkmf.rb: libpath_env

* lib/mkmf.rb (MakeMakefile#libpath_env): ignore empty LIBPATHENV.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39574 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* encoding.c: Typo in Encoding overview by Tom Wardrop [GH fixes #255]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39575 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* 2013-03-04

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39576 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
ChangeLog: fix commit miss

* ChangeLog: remove duplicated entry by commit miss.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39577 b2dd03c8-39d4-4d8f-98ff-823fe69b080e