Release 2.0-RC2

Update changelog for 2.0-RC1

Fix "text" selector

"text" selectors currently return no matches.

This commit contains a partial backport of b50d97b, which specifically
fixes "text" selectors".

References [bugs:#175]

Release 1.9

Bump version to 1.8.1

Release 1.8

Release 1.7

Fix the content-type to be case insensitive.

updat ehte change log a little tiny bit.