Enhancements

Fix when subscription download timeout before complete, the parser will still try to parse downloaded content.
Change default regex library to PCRE2.
Change Quantumult X "url-test" equivalent to "available".
Optimize codes.
Update build scripts.

cmake/FindJPCRE2.cmake

@@ -0,0 +1,27 @@
+# - Find JPCRE2
+# Find the JPCRE2 headers.
+#
+#  JPCRE2_INCLUDE_DIRS - where to find jpcre2.h.
+#  JPCRE2_FOUND        - True if JPCRE2 found.
+
+# Look for the header file.
+FIND_PATH(JPCRE2_INCLUDE_DIR NAMES jpcre2.hpp)
+MARK_AS_ADVANCED(JPCRE2_INCLUDE_DIR)
+
+if(JPCRE2_INCLUDE_DIR)
+  set(JPCRE2_FOUND TRUE)
+endif()
+
+IF(JPCRE2_FOUND)
+  SET(JPCRE2_INCLUDE_DIRS ${JPCRE2_INCLUDE_DIR})
+ENDIF(JPCRE2_FOUND)
+
+if(JPCRE2_FOUND)
+  if(NOT JPCRE2_FIND_QUIETLY)
+    message(STATUS "Found JPCRE2 header files in ${JPCRE2_INCLUDE_DIRS}")
+  endif()
+elseif(JPCRE2_FIND_REQUIRED)
+    message(FATAL_ERROR "Could not find JPCRE2")
+else()
+  message(STATUS "Optional package JPCRE2 was not found")
+endif()