Added flags parameter to format_hex_ex.

We add the flags parameter without changing the signature of
the function by repurposing the space_break parameter into
space_break_flags where the lower 8 bits are used for the
previous space_break parameter and the higher bits are used
for flag values.

Added new flag FHE_CAPS that formats the generated hex string
in upper case.

Signed-off-by: James Yonan <james@openvpn.net>
PolarSSL x509_get_sha1_hash now returns correct SHA1 fingerprint.

Signed-off-by: James Yonan <james@openvpn.net>
Implemented x509-track for PolarSSL.

Signed-off-by: James Yonan <james@openvpn.net>