Increase logging if error encountered during POSIX library loading

[tgd]

In some instances the POSIX library will fail to load appropriately. One recent example is if an application using the POSIX library is run from a part of the filesystem that has the noexec flag. In this situation, and if no SLF4J implementation is available, no warnings or error will be shown in standard out or standard error.

In the case where POSIX can not be loaded at application initialization downstream callsites will encounter a NullPointerException when making POSIX calls. One such call site is found in queue - when the appender closes it calls msync.