Show IE 8+ compatibility mode users a better error

* Currently IE 8,9,10,11 etc users will see an 'IE 7 is not supported' message if they try and view a timeline while IE's compatibility mode is enabled.
* This is confusing as the user knows they are not using IE7.
* This commit alters the error message to include the sentence 'If you are using a recent version of Internet Explorer you may need to disable compatibility mode in your browser.'
* I haven't provided a link to guidance on how to do this as there doesn't seem to be an official Microsoft source on how to *disable* compatibility mode, and I didn't want to link to an unofficial source that might become unavailable in the future.
Merge pull request #617 from pwolstenholme/patch-1

Show IE 8+ compatibility mode users a better error