src/daemon/utils_time.h: Treat nanoseconds as 64bit integer.

src/daemon/utils_time.h: Treat nanoseconds as 64bit integer.

The assumed type was "long", because that is what struct timespec is
using. However, struct timespec only stores the fraction of a second in
the approrpiate field and therefore only cares about values up to 10^9.
We, on the other hand, assume a UNIX epoch in ns precision, so we
require the entire 64bits.

This patch changes the [MUN]S_TO_CDTIME_T() macros to assume a uint64_t
input and moves the casting to the appropriate data type for struct
time{val,spec} to the CDTIME_T_TO_TIME{VAL,SPEC}() macros. Appropriate
casts are added to the cURL based plugins which need to pass a "long" to
cURL when specifying timeouts.

It also fixes the unit test, which assigned large (> 32 bit) literals to
a "long" field, which breaks on 32 bit architectures.