Refactor FastCGI server and compiler, enhance HTTP header parsing, and add WebSocket support

- Refactored FastCGIServer class to improve socket handling and added shutdown functionality.
- Updated compiler functions to streamline HTML and text literal processing.
- Enhanced split_kv function to support uppercase keys and added split_http_headers for better HTTP header parsing.
- Introduced new session management functions to validate and handle session IDs.
- Added WebSocket frame parsing and handling in the URI module.
- Created systemd service scripts for easier deployment and management of the UCE FastCGI runtime.
- Added new test cases for header handling, time parsing, and WebSocket functionality.

doc/pages/ob_clear.txt

@@ -1,11 +0,0 @@
-:sig
-void ob_clear()
-
-:params
-(none)
-
-:desc
-Discard the current output buffer.
-
-:see
->ob

doc/pages/ob_close.txt

@@ -0,0 +1,11 @@
+:sig
+void ob_close()
+
+:params
+(none)
+
+:desc
+Discard the current output buffer. If are more output buffers on the stack, switch to the next one.
+
+:see
+>ob

doc/pages/ob_get_close.txt

@@ -1,11 +1,12 @@
 :sig
-String ob_get_clear()
+String ob_get_close()
 
 :params
 return value : content of the current output buffer
 
 :desc
 Returns the contents of the current output buffer and then discards the buffer.
+If are more output buffers on the stack, switch to the next one.
 
 :see
 >ob

doc/pages/ob_start.txt

@@ -5,7 +5,7 @@ void ob_start()
 (none)
 
 :desc
-Starts a new output buffer. All subsequent output will be directed into this buffer.
+Starts a new output buffer. All subsequent output will be directed into this buffer. Every call to ob_start() starts a new buffer and puts that buffer on the output buffer stack. ob_close() and ob_get_close() destroy buffers and remove them from the stack.
 
 :see
 >ob