Make KSCrashReportStore.h a public header

KSCrashAdvanced.h imports KSCrashReportStore.h, so adding the framework
to a project and attempting to compile fails when using the delayed sink
installation example in the Readme. Making KSCrashReportStore.h a public
header included in the Headers folder of the framework solves this issue.
Merge pull request #12 from holdtotherod/master

Make KSCrashReportStore.h a public header