COMP: External_curl - Explicitly pass -fPIC flag on x86_64 platform

This commit will fix the following link error:

/usr/bin/ld: /home/jchris/Projects/Slicer-SuperBuild-Debug-Qt485-new-buildsystem/curl-build/lib/libcurl.a(easy.c.o): relocation R_X86_64_32S against `malloc' can not be used when making a shared object; recompile with -fPIC
/home/jchris/Projects/Slicer-SuperBuild-Debug-Qt485-new-buildsystem/curl-build/lib/libcurl.a: error adding symbols: Bad value
collect2: error: ld returned 1 exit status

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22733 3bd1e089-480b-0410-8dfb-8563597acbee
COMP: Explicitly link RemoteIO against OpenSSL

Given that since commit r22724  curl library is linked against OpenSSL
and that since commit r22732 it is statically built. This commit
explicitly link the shared library RemoteIO against OpenSSL
because the curl static library doesn't provide information how to
resolve the OpenSSL symbol.

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22734 3bd1e089-480b-0410-8dfb-8563597acbee
COMP: External_curl - Build only http/https support to avoid link error

By default, curl will try to build all supported features. Since only
http/https protocol is needed, let's simply disable the other feature
to avoid extra dependency to library like "ldap", "idn" ...

See #1739

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22735 3bd1e089-480b-0410-8dfb-8563597acbee