Increase numeric-timestamp precision to nanoseconds

Tidied and standardised text_helper implementations.

Redirect route inspect

This commit fixes route inspection in `rake routes`

Before:

  foo  /foo(.:format) :controller#:action"

After:

  foo  /foo(.:format)  Redirect (301)

wrap time ranges with timezones

Fix warning: possibly useless use of % in void context

Fix build: can't convert Regexp to String

Bug #6289

NumberHelper.number_with_delimiter should html_escape both delimiters and separators

reverting decoupling of NumberHelper from safe_join and adding tests for escaping of delimiters and separators

Refactor migration generator

doesn't modify params in SafeBuffer#%

when we pass fractional usec to Time methods we should use Rational
instead of Float because of accuracy problem

    Time.local(2011,6,12,23,59,59,999999.999).nsec
    # => 999999998

    Time.local(2011,6,12,23,59,59,Rational(999999999, 1000)).nsec
    # => 999999999

AS::Callbacks: fix run_callbacks for objects with negative id

Add some common Array methods to the middleware stack

Render img tag with empty src if empty string is passed to image_tag.

The docs suggest that the middleware stack is an Array, so I've added
the unshift method to it. Originally I added some more Array methods,
but it was agreed that they lacked usecases.

Add HTML5 input[type="time"] helper

Removed old text_helper apis for highlight, excerpt and word_wrap

Fix incorrect assert_block -> assert conversion. Assumed too much from the MiniTest deprecation message.

Reverted changes:
  f3482a9f Fix tests in railties
  5904295b improve #6318
  aed906af prevent using already loaded Gemfile for 'bundle install'

In order to fix this, we need a fix in bundler related to GEM_PATH,
which will allow to run tests properly. I will get this changes back
when it happens.