[WK2] Add ENABLE_NETWORK_PROCESS flag
https://bugs.webkit.org/show_bug.cgi?id=125421

Add support to build with the Network Process enabled.

Patch by Brian Holt <brian.holt@samsung.com> on 2013-12-08
Reviewed by NOBODY (OOPS!).

* Scripts/webkitperl/FeatureList.pm:
[WK2] Guard Mac specific network process code with PLATFORM(MAC)
https://bugs.webkit.org/show_bug.cgi?id=125422

Mac specific code should be guarded to prevent compile failures on other platforms.

Patch by Brian Holt <brian.holt@samsung.com> on 2013-12-08
Reviewed by NOBODY (OOPS!).

* NetworkProcess/NetworkResourceLoader.cpp:
(WebKit::NetworkResourceLoader::continueWillSendRequest):
* WebProcess/Network/WebResourceLoader.cpp:
(WebKit::WebResourceLoader::didReceiveResponseWithCertificateInfo):
[WK2][Gtk] Add support for ENABLE_NETWORK_PROCESS to the build system
https://bugs.webkit.org/show_bug.cgi?id=118231

Patch by Brian Holt <brian.holt@samsung.com> on 2013-12-08
Reviewed by NOBODY (OOPS!).

Original patch by Kwang Yul Seo  <skyul@company100.net>.

.:

Disabled ENABLE_NETWORK_PROCESS by default.

* Source/autotools/SetupAutomake.m4:
* Source/autotools/SetupWebKitFeatures.m4:

Source/WebKit2:

Add source files to the build system and build NetworkProcess executable.

* GNUmakefile.am:
* GNUmakefile.list.am:
* NetworkProcess/unix/NetworkProcessMainUnix.cpp:
* UIProcess/gtk/WebContextGtk.cpp:
(WebKit::WebContext::platformInitializeWebProcess):