Log Message:
Updated curl to 7.50.3.

Curl and libcurl 7.50.3

This release includes the following bugfixes:

 o CVE-2016-7167: escape and unescape integer overflows [8]
 o mk-ca-bundle.pl: use SHA256 instead of SHA1
 o checksrc: detect strtok() use
 o errors: new alias CURLE_WEIRD_SERVER_REPLY [1]
 o http2: support > 64bit sized uploads [2]
 o openssl: fix bad memory free (regression) [3]
 o CMake: hide private library symbols [4]
 o http: refuse to pass on response body with NO_NODY was set [5]
 o cmake: fix curl-config --static-libs [6]
 o mbedtls: switch off NTLM in build if md4 isn't available [7]
 o curl: --create-dirs on windows groks both forward and backward slashes [9]