changed heredoc support

now the input string is kept intact until the end of the input is reached
this enables the history buffer to store the complete command
Still broken:
history buffer with heredoc wont execute because the delimiter is not determined correctly
editing of multiline things

example/main.c

@@ -42,7 +42,7 @@ void set_blocking (int fd, int should_block)
 
 static shellmatta_retCode_t doSomething(shellmatta_handle_t handle, const char *arguments, uint32_t length)
 {
-
+    shellmatta_printf(handle, "%s - length: %u", arguments, length);
     return SHELLMATTA_OK;
 }
 shellmatta_cmd_t doSomethingCmd = {"doSomething", "do", "Function does something", "use me, please", doSomething, NULL};
@@ -79,7 +79,7 @@ int main(void)
     static char historyBuffer[4096];
     static shellmatta_instance_t instance;
 
-    f = open("/dev/pts/1", O_RDWR | O_SYNC);
+    f = open("/dev/pts/3", O_RDWR | O_SYNC);
 
     if (f < 0)
     {