Typecast when converting to int from long to avoid some compiler warnings

The test code that was #ifdef'ed in the code was converted into unit
tests in test case 1309. I also removed the #if 0'ed code from splay.c

With "@unittest: [num]" in the header comment for each tested function.
Shows we have a log way to go still...

When closing a connection, the speedchecker's timestamp is now deleted
so that it cannot accidentally be used by a fresh connection on the same
handle when examining the transfer speed.

Bug: https://bugzilla.redhat.com/679709

When a time condition isn't met, so that no body is delivered to the
application even though a 2xx response is being read from the server, we
must close the connection to avoid a re-use of the connection to be
completely tricked.

Added test 1128 to verify.

Typecasts added since I changed more code to use long for timeouts

It was mostly typecasted to int all over the code so switching to long
instead all over should be a net gain.

I removed the prefix as well accordingly.

Fix compiler warning: cast increases required alignment

Source files given with relative paths do not have the
-D directory specifier prepended.

Fix compiler warning: conversion may lose significant bits

When switching to HTTP because a HTTP proxy is being used, the existing
handler is now checked if it already is "compatible". This allows the https
handler remain while other non-http handlers will be redirected.

Bug: http://curl.haxx.se/mail/lib-2011-05/0214.html
Reported by: Jerome Robert

Fix compiler warning: variable was set but never used

Fix compiler warning: clobber ignored

Fix compiler warning: variable was set but never used

Fix compiler warning: clobber ignored

Enclose header file in an inclusion guard

Fix compiler warning: expression has no effect

Fix compiler warning: `keycheck' might be used uninitialized in this function.
Fix compiler warning: `keybit' might be used uninitialized in this function.

Fix variable declaration placement

Fix missing semicolon

Fix compiler warning: expression has no effect

Fix OOM handling

Fix compiler warning: expression has no effect

Fix compiler warning: unused variable 'data'

Fix compiler warning: enumerated type mixed with another type

Fix compiler warning: enumerated type mixed with another type

Fix compiler warning: enumerated type mixed with another type

Fix compiler warning: enumerated type mixed with another type

Fix compiler warning: empty body in an if-statement