[PATCH] core: enable unsolicited messages on secondary

Previously the enable unsolicited messages command (+CNMI) was only being sent on the primary. This patch adds support for sending the enable on the secondary as well. If the secondary doesn't exist, or if setting the enable causes an error, a warning is logged but no error is propogated up. This

[PATCH] core: process SMS +CGMR response with regex

Variability in the response style from certain modems would cause the parsing of the +CGMR response to fail. For example, the Telit HE910 inserts an empty string ("") in the second field of the response, which caused the previous sscanf implementation to fail. This patch converts the parsing of