remove some redundant declarations
remove extra semicolons
spo_alert_fwsam: a few small fixes.

fix: if statement with empty body (i.e. no effect)
fix: strcpy with overlapping buffers
fix: prefer strnlen over strlen.
convert fn() prototypes to fn(void)
fix: do not equate a float to an int
build: compile as gnu99
remove unsupported databases: ODBC, MSSQL, Oracle
build: gcc warnings with --enable-debug
Merge branch 'remove-unsupported-db'
fix: bump schema version
spo_database: rewrite escaping for db queries

Rewrite escaping to use "parametized" queries with format string like
syntax allowing strings to be escaped and put into the query in one
step.