+ Move type CommandInfo from GF.Command.Commands to a new module
GF.Commands.CommandInfo and make it independent of the PGF type.
+ Make the module GF.Command.Interpreter independent of the PGF type and
eliminate the import of GF.Command.Commands.
+ Move the implementation of the "help" command to its own module
GF.Command.Help
+ References to modules under src/compiler have been eliminated from the PGF
library (under src/runtime/haskell). Only two functions had to be moved (from
GF.Data.Utilities to PGF.Utilities) to make this possible, other apparent
dependencies turned out to be vacuous.
+ In gf.cabal, the GF executable no longer directly depends on the PGF library
source directory, but only on the exposed library modules. This means that
there is less duplication in gf.cabal and that the 30 modules in the
PGF library will no longer be compiled twice while building GF.
To make this possible, additional PGF library modules have been exposed, even
though they should probably be considered for internal use only. They could
be collected in a PGF.Internal module, or marked as "unstable", to make
this explicit.
+ Also, by using the -fwarn-unused-imports flag, ~220 redundant imports were
found and removed, reducing the total number of imports by ~15%.
An apparent bug in ghc-7.2.2 causes the type Value to be exported from PGF.Data.
Workaround: restrict the imports from PGF.Data in GF.Command.Abstract and
GF.Compile.GeneratePMCFG to avoid the clash with locally defined type Value.
(ghc-7.0.4 and ghc-7.4.1 appear to be free from this bug.)
