parseChain() PEM update

parseChain() PEM update

parseChain() from ca_adapter_net_tls.c modified in order to parse
PEM certificates. Input buffer may contain either PEM or DER
certificates in a jumble. Each PEM format certificate in a chain
must be terminated with null byte.

Change-Id: Id0e7ff5dddf4af4213dfb0ffe8a8ca05f96581a7
Signed-off-by: Oleksii Beketov <ol.beketov@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/10741
Reviewed-by: Jon A. Cruz <jon@joncruz.org>
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Joonghwan Lee <jh05.lee@samsung.com>
Reviewed-by: dongik Lee <dongik.lee@samsung.com>
Reviewed-by: Dmitriy Zhuravlev <d.zhuravlev@samsung.com>