Clarify deferred server reporting

It is necessary to call -sendAllReportsWithCompletion: on the KSCrash instance when using deferred reporting. This clarifies advanced usage a bit.
Merge pull request #14 from holdtotherod/patch-1

Clarify deferred server reporting documentation
Fixed MFMailComposeViewController leak in KSCrashReportSinkEMail.m
Merge pull request #16 from JaviSoto/patch-1

Fixed MFMailComposeViewController leak in KSCrashReportSinkEMail.m
Merge branch 'master' into feature/revamped-api

Conflicts:
	KSCrash/KSCrash/KSCrashReportSinkEMail.m
	README.md
Commented out quincy URLs used in local test rig.
Fixed misnamed method.