unit tests: switch time zone to GMT as it is the default when java.util.TimeZone is dysfunctional; fix several tests with incorrect placement of 'na.rm=XX'; fix several syntax errors in tests

remove explicit paths for the ASM libraries; add com.oracle.truffle.r.release project; remove FASTR distribution; add FASTR_RELEASE distribution; add custom projects for native/release

Two filtering options added to the RBuiltinDiagnostics allowing ignoring RNull and RMissing argument types.

No need to print stack trace to the file when running tests (that actually generate errors on purpose).