manipulation: Add Append*() functions
filter: Add *Selector for filtering methods that accepts a pre-compiled cascadia selector.
manipulation: Add Remove*() functions.
manipulation: Add Empty() function.
manipulation: Add After*() functions.
manipulation: Add Before*() functions.
property: Add/Remove/Toggle Class functions
property: Add Set/Remove Attr functions
Update documentation to include manipulation functions
Merge branch 'master' into manipulation
start adding matcher functions
finish transition for Matcher-based overloads
add Go 1.3 target in travis tests
make test assert helpers private
remove lint warning
rename NewDocumentFromDocument to CloneDocument
fix failing test due to CloneDocument renaming
doc
fix class manipulation issue
more *Matcher overloads of selector string methods