- Generate VQUIC and VSSH filenames in Visual Studio project files.

Prior to this change generated Visual Studio project configurations that
enabled SSH did not build properly. Broken since SSH files were moved to
lib/vssh 3 months ago in 5b2d703.

Fixes https://github.com/curl/curl/issues/4492
Fixes https://github.com/curl/curl/issues/4630
Closes https://github.com/curl/curl/pull/4607

Closes #854

After squashing most of our compiler warnings, up'ed the default
warning level from 3 to 4 in order to increase the likelyhood of
catching future warnings.

Updated the makefiles and Visual Studio project files to support moving
the authentication code to the new lib/vauth directory that was started
in commit 0d04e859e1.

find . -name .gitignore -print0 | xargs -i -0 sort -o '{}' '{}'

This wasn't possible with the old curlsrc project filenames, but like
commit 2a615a2b64 and 11397eb6dd for libcurl use the built in Visual
Studio macros for the output filenames.

Following commit 957fcd9049 and in preparation for adding the VC14
project files renamed the curl source project files.

Prior to this change some Release configurations had an active
configuration assignment to their Debug counterpart.

In addition to commit 709cf76f6b, removed the USE_SSLEAY preprocessor
variable from the Visual Studio project files as it isn't required
anymore.

Visual Studio 2005 and above defaults to disabling the startup banner
for the Compiler, Linker and MIDL tools (with /NOLOGO). As such there
is no need to explicitly set the SuppressStartupBanner directive, as
this is a leftover from the VC7 and VC7.1 projects being upgraded to
VC8 and above.