Merge pull request #114 from zolkis/gh-pages

small fixes
Added Changes section and related text (closes #116)

Please note that tidy cleaned up some recent commits.
Small markup fixes and corrections
Changed ILLEGAL_STATE to InvalidStateError (closes #118)
more markup fixes
Fixed code/dfn -> dfn/code for consistancy
tidy
resolver should be a variable not emphasis
Fixed links to promises
Added link to DOM4 resolver. (closes #119)
tidy
Made DOM4 a normative reference
replaced property for attribute
tidy
error should be a variable
Linked up "default telefony service" in a few places
removed some redundant markup
Removed some more redundant markup.
Changed simple event to Event (closes #121)
Removed NoInterfaceObject from CallHistoryEntry (closes #122)