Fix out of bound indices in parse::is_date().
Fix out of bound indices in parse::is_date().

Don't access possibly invalid indices in to_match string. This happily
accessed out of bound memory when parsing something as simple as "foo = 1", so
check the string length first, before looking at its contents.

skystrife/cpptoml,zzzworm/cpptoml,skystrife/cpptoml,vadz/cpptoml,Nephatrine/cpptoml,Payshare/cpptoml,Payshares/cpptoml,vadz/cpptoml,Nephatrine/cpptoml