etc/options

--- a/etc/options	Tue Jan 29 22:47:45 2019 +0100
+++ b/etc/options	Wed Jan 30 13:25:33 2019 +0100
@@ -113,9 +113,6 @@
 option process_output_tail : int = 40
   -- "build process output tail shown to user (in lines, 0 = unlimited)"
 
-option checkpoint : bool = false
-  -- "checkpoint for theories during build process (heap compression)"
-
 option profiling : string = ""
   -- "ML profiling (possible values: time, allocations)"