No longer open signature files when reopening a solution

Reference at
https://social.msdn.microsoft.com/Forums/vstudio/en-US/d5c0c7e6-8b3c-48c3-ac1c-43dd713c0129/using-ivsuishellopendocumentopenspecificeditor-with-vsrdtflagsrdtdontautoopen-?forum=vsx
Dispose resources
Set cursor positions when going to Metadata

Close #683.
Improve precision of cursor positions
Update docs and release notes
Match symbols using tryGetFullyQualifiedName
Merge pull request #906 from dungpa/misc

Improve Go to Metadata