* add WC_SIG_IGNORE_BEGIN(), WC_SIG_IGNORE_END(), wc_linuxkm_sig_ignore_begin(), wc_linuxkm_sig_ignore_end();
* move WC_CHECK_FOR_INTR_SIGNALS() and WC_RELAX_LONG_LOOP() definitions outside the BUILDING_WOLFSSL gate;
* refactor linuxkm_lkcapi_registering_now as a wolfSSL_Atomic_Int and use it as a mutex for linuxkm_lkcapi_register() and linuxkm_lkcapi_unregister();
* add WC_SIG_IGNORE_BEGIN()...WC_SIG_IGNORE_END() wrappers around all relevant critical spans in linuxkm glue.