Additional mime-specific tests.
Existing tests updated to reflect small differences (Expect: 100-continue,
data size change due to empty lines, etc).
Option -F headers= keyword added to tests.
test1135 disabled until the entry point order change is resolved.
New example smtp-mime.
Examples postit2 and multi-post converted from form API to mime API.

The -F option allows some custom parameters within the given string, and
those strings are separated with semicolons. You can for example specify
"name=daniel;type=text/plain" to set content-type for the
field. However, the use of semicolons like that made it not work fine if
you specified one within the content-type, like for:
"name=daniel;type=text/plain;charset=UTF-8"
... as the second one would be seen as a separator and "charset" is no
parameter curl knows anything about so it was just silently discarded.

The new logic now checks if the semicolon and following keyword looks
like a parameter it knows about and if it isn't it is assumed to be
meant to be used within the content-type string itself.

I modified test case 186 to verify that this works as intended.

Reported by: Larry Stone
Bug: http://curl.haxx.se/bug/view.cgi?id=3048988

are not, due mainly to the lack of support for XML character entities
(e.g. & => & ).  This will make it easier to validate test files using
tools like xmllint, as well as edit and view them using XML tools.

responded with a single status line and no headers nor body. Starting now, a
HTTP response on a persistent connection (i.e not set to be closed after the
response has been taken care of) must have Content-Length or chunked
encoding set, or libcurl will simply assume that there is no body.

To my horror I learned that we had no less than 57(!) test cases that did bad
HTTP responses like this, and even the test http server (sws) responded badly
when queried by the test system if it is the test system. So although the
actual fix for the problem was tiny, going through all the newly failing test
cases got really painful and boring.

A) Normal non-proxy HTTP:

 - no more "Pragma: no-cache" (this only makes sense to proxies)

B) Non-CONNECT HTTP request over proxy:

 - "Pragma: no-cache" is used (like before)
 - "Proxy-Connection: Keep-alive" (for older style 1.0-proxies)

C) CONNECT HTTP request over proxy:

 - "Host: [name]:[port]"
 - "Proxy-Connection: Keep-alive"