Cope with raw sources that were read with the wrong encoding.

Force raw message source to binary encoding before doing CRLF
conversion, masking common issues when users read a message using the
default external encoding (UTF-8), resulting in invalid UTF-8 characters
that break the regexp used for CRLF conversion.

Fixes #736.
Merge pull request #681 from srawlins/allocate-less-things

Allocate less things

Conflicts:
	lib/mail/fields/common/common_field.rb
	lib/mail/utilities.rb
Loosen Travis-CI ruby versions; fix 1.9.2 not installable
autoload parsers for load-time speed and memory usage
Update CHANGELOG

[ci skip]
Bump to 2.6.2; update changelog
Merge branch '2-6-stable'

Conflicts:
	VERSION
	lib/mail/constants.rb
	lib/mail/elements/address.rb
	lib/mail/fields/common/parameter_hash.rb
	lib/mail/version.rb