mruby-print: disable the gem unless explicitly specified

mruby-print is the duplicate of part of mruby-io. You need it only when
limited I/O functionality required.

mrbgems/full-core.gembox

@@ -1,6 +1,6 @@
 MRuby::GemBox.new do |conf|
   Dir.glob("#{root}/mrbgems/mruby-*/mrbgem.rake") do |x|
     g = File.basename(File.dirname(x))
-    conf.gem :core => g unless g =~ /^mruby-(?:bin-debugger|test)$/
+    conf.gem :core => g unless g =~ /^mruby-(?:bin-debugger|test|print)$/
   end
 end

mrbgems/mruby-bin-mruby/mrbgem.rake

@@ -4,7 +4,6 @@ MRuby::Gem::Specification.new('mruby-bin-mruby') do |spec|
   spec.summary = 'mruby command'
   spec.bins = %w(mruby)
   spec.add_dependency('mruby-compiler', :core => 'mruby-compiler')
-  spec.add_test_dependency('mruby-print', :core => 'mruby-print')
 
   if build.cxx_exception_enabled?
     build.compile_as_cxx("#{spec.dir}/tools/mruby/mruby.c")

mrbgems/mruby-print/mrbgem.rake

@@ -1,5 +1,6 @@
 MRuby::Gem::Specification.new('mruby-print') do |spec|
   spec.license = 'MIT'
   spec.author  = 'mruby developers'
-  spec.summary = 'standard print/puts/p'
+  spec.summary = 'minimal print/puts'
+  # mruby-io provides full I/O functionality
 end

mrbgems/stdlib-io.gembox

@@ -7,9 +7,6 @@ MRuby::GemBox.new do |conf|
   # Use standard IO/File class
   conf.gem :core => "mruby-socket"
 
-  # Use standard print/puts/p
-  conf.gem :core => "mruby-print"
-
   # Use errno extension for a good mruby-io/mruby-socket experience
   conf.gem :core => "mruby-errno"
 

test/t/kernel.rb

@@ -59,11 +59,11 @@ assert('Kernel.loop', '15.3.1.2.8') do
   assert_equal 100, i
 end
 
-# Kernel.p is provided by the mruby-print mrbgem. '15.3.1.2.9'
+# Kernel.p is provided by the mruby-io mrbgem. '15.3.1.2.9'
 
-# Kernel.print is provided by the mruby-print mrbgem. '15.3.1.2.10'
+# Kernel.print is provided by the mruby-io mrbgem. '15.3.1.2.10'
 
-# Kernel.puts is provided by the mruby-print mrbgem. '15.3.1.2.11'
+# Kernel.puts is provided by the mruby-io mrbgem. '15.3.1.2.11'
 
 assert('Kernel.raise', '15.3.1.2.12') do
   assert_raise RuntimeError do
@@ -377,11 +377,11 @@ assert('Kernel#object_id', '15.3.1.3.33') do
   assert_kind_of Numeric, 1.0.object_id
 end
 
-# Kernel#p is defined in mruby-print mrbgem. '15.3.1.3.34'
+# Kernel#p is defined in mruby-io mrbgem. '15.3.1.3.34'
 
-# Kernel#print is defined in mruby-print mrbgem. '15.3.1.3.35'
+# Kernel#print is defined in mruby-io mrbgem. '15.3.1.3.35'
 
-# Kernel#puts is defined in mruby-print mrbgem. '15.3.1.3.39'
+# Kernel#puts is defined in mruby-io mrbgem. '15.3.1.3.39'
 
 assert('Kernel#raise', '15.3.1.3.40') do
   assert_raise RuntimeError do