Use simpler method for computing letter from number

Author: livecodeali

.travis.yml

@@ -49,6 +49,10 @@ script: |
   esac
   export MODE=debug
   _download/livecode-community-server tests/_testrunner.lc run tests/test-scripts
+  if [ $? -ne 0 ] ; then
+      cat tests/_test_suite.log
+      exit 1
+  fi
 
 addons:
   # Packages needed for building LiveCode

src/PuzzleTools.livecodescript

@@ -12,7 +12,7 @@ end toNumber
 
 function fromNumber pNum
    local tNum
-   put ((pNum - 1) mod 26) + 65 into tNum
+   put (pNum mod 27) + 64 into tNum
    return numtochar(tNum)
 end fromNumber