Remove advice to use sudo when installing the gem

Installing gems with sudo strikes me as a bad thing.
Merge pull request #927 from parndt/patch-1

Remove advice to use sudo when installing the gem
Merge pull request #928 from abotalov/master

Document actual within_frame support
update RSpec examples
Merge pull request #929 from JoelQ/documentation-update

update RSpec examples
Remove broken selector
Merge pull request #931 from abotalov/remove_content_selector

Remove broken :content selector
Clean up Capybara::RackTest::Node#set
Merge pull request #933 from jamescook/cleanup_set_method

Clean up Capybara::RackTest::Node#set
Color values are serialized in lowercase

According to the spec [1], color values are serialized in lowercase.
capybara-webkit returns lowercase values when compiled against Qt 5,
while Firefox and Qt 4 return the initial, uppercase value.

[1] http://goo.gl/2GK9o
Merge pull request #939 from mhoran/master

Color values are serialized in lowercase
Adding documentation for Capybara::Result to be more explicit about what
Node#all returns.
Added disabled? to simple node
Added disabled? to the node
Added disabled? to driver
Delegate to the native check for enabled
Removed spec to cover empty disabled attributes due to nokogiri jruby.
Add #title method to Capybara::Node::Document
support form attribute for submit buttons
Update lib/capybara/node/matchers.rb

The example given for has_selector? with a count is misleading. As it specifies "p#foo", this is referring to a p element with an id of "foo". This should only appear once on a page.