catch SIGTERM meant for running process

stdlib/stdlib.go

@@ -18,6 +18,7 @@
 package stdlib
 
 import (
+    "os"
     "git.callpipe.com/aidan/shs/ast"
 )
 
@@ -116,10 +117,10 @@ func GenFuncTable() ast.FuncTable {
         },
 
         "exit": &ast.Function{
-            Function:     exit,
-            Name:       "exit",
-            TimesCalled      0,
-            Args:            0,
+            Function: exit_shell,
+            Name:         "exit",
+            TimesCalled:       0,
+            Args:              0,
         },
     }