Integration - attribute validation

- Implemented digitsOnly primitive.
- Implemented noSpaces primitive.
- Added unit tests for above.
- Att now manages the lists of valid attributes and modifier names.
- validName migrated to Att.
- validModifiableName migrated to Att.
- New Att::validNameValue.
- Removed obsolete validDescription.
- Removed obsolete validPriority.
- Removed obsolete valid.cpp/guess.
- Implemented text.cpp/noVerticalSpace.
- Added unit tests for text.cpp/noVerticalSpace.
- Removed final static lists from valid.cpp.

src/edit.cpp

@@ -35,6 +35,7 @@
 #include <string.h>
 #include "T.h"
 #include "Date.h"
+#include "Duration.h"
 #include "text.h"
 #include "util.h"
 #include "main.h"
@@ -211,7 +212,7 @@ static void parseTask (T& task, const std::string& after)
   {
     if (value != "")
     {
-      if (validPriority (value))
+      if (Att::validNameValue ("priority", "", value))
       {
         std::cout << "Priority modified." << std::endl;
         task.setAttribute ("priority", value);
@@ -392,7 +393,8 @@ static void parseTask (T& task, const std::string& after)
   {
     if (value != "")
     {
-      if (validDuration (value))
+      Duration d;
+      if (d.valid (value))
       {
         std::cout << "Recurrence modified." << std::endl;
         if (task.getAttribute ("due") != "")