Add HTTP/HTTPS Fetch() API to redbean

You can now say the following in your redbean Lua code:

    status,headers,payload = Fetch("https://foo.example")

The following Lua APIs have been introduced:

  - Fetch(str) → str,{str:str},str
  - GetHttpReason(int) → str
  - GetHttpReason(int) → str
  - ProgramSslFetchVerify(bool)
  - ProgramSslClientVerify(bool)

The following flags have been introduced:

  - `-j` enables client SSL verification
  - `-k` disables Fetch() SSL verification
  - `-t INT` may now be passed a negative value for keepalive

Lua exceptions now invoke Cosmopolitan's garbage collector when
unwinding the stack. So it's now safe to use _gc() w/ Lua 𝔱𝔥𝔯𝔬𝔴

See #97

net/net.mk

@@ -2,4 +2,5 @@
 #───vi: set et ft=make ts=8 tw=8 fenc=utf-8 :vi───────────────────────┘
 
 .PHONY: 	o/$(MODE)/net
-o/$(MODE)/net:	o/$(MODE)/net/http
+o/$(MODE)/net:	o/$(MODE)/net/http	\
+		o/$(MODE)/net/https