Fix typo: SIGURS1 should be SIGUSR1
grammar and readability

corrected verb agreement ("are still require" -> "still require") and adjusted punctuation to improve sentence division and readability 
Add - to tar to read from stdin 
merge: signal typo fix
merge: typo fix
merge: minor fix
Update source/reference/command/compact.txt

Changed the note about the status change for a compact to be a warning 
and altered the case of the states to make it more in line with what 
is actually displayed in rs.status() and added a link to the state 
definitions for more info.
DOCS-937: fixing error page processing
merge: DOCS-936
DOCS-931: reindex propogation
DOCS-915 clarifying example
DOCS-883 add db.serverBuildInfo()
Fix typo in source/reference/operator/all.txt
DOCS-944 fix epub build process
DOCS-931 error page directory copies safely
build: fixing tar compatibility problem
merge: DOCS-883
DOCS-883 edits to buildinfo
merge: typo fix
DOCS-923: duplicate field name note