Enhancements - Cmd object

- New Cmd object to handle localized commands, customReports and general
  command parsing.
- Localized new Subst methods.
- Relocate guess method from parse.cpp to text.cpp.
- Converted Att object to use new valid/parse scheme.
- Unit tests for Cmd object.
- Fixed att.t.cpp unit tests.

src/Makefile.am

@@ -2,10 +2,10 @@ bin_PROGRAMS = task
 task_SOURCES = Config.cpp Date.cpp Record.cpp T.cpp T2.cpp TDB.cpp TDB2.cpp   \
                Att.cpp Filter.cpp Sequence.cpp Table.cpp Grid.cpp Timer.cpp   \
                Duration.cpp StringTable.cpp Location.cpp Subst.cpp Keymap.cpp \
-               Nibbler.cpp Context.cpp color.cpp parse.cpp task.cpp edit.cpp  \
-               command.cpp report.cpp util.cpp text.cpp rules.cpp import.cpp  \
-               interactive.cpp                                                \
+               Nibbler.cpp Context.cpp Cmd.cpp color.cpp parse.cpp task.cpp   \
+               edit.cpp command.cpp report.cpp util.cpp text.cpp rules.cpp    \
+               import.cpp interactive.cpp                                     \
                Config.h Date.h Record.h T.h TDB.h Att.h Filter.h Sequence.h   \
                Table.h Grid.h Timer.h Duration.h StringTable.h Location.h     \
-               Subst.h Keymap.h Nibbler.h Context.h color.h task.h
+               Subst.h Keymap.h Nibbler.h Context.h Cmd.h color.h task.h