Miscellaneous utility functions in OCaml for Marionnet

 This OCaml library provides a set of needed and useful macros for developing.
 It is mainly used by the marionnet package.
 Modules and functionality are the following :
 .
  - Configuration_files: Allow to get information from configuration files
  - Environments: Environments are useful for maintaining the state, intendend
 as a set of bindings, of a user interaction with a GUI
  - FilenameExtra: Additional features for the standard module Filename
  - Fix: Poor man fix point operators
  - Hashm[m]ap: 2 Module implementing polymorphic unbounded (multi) maps
  - Hashset: Very simple module implementing a polymorphic unbounded sets
  - Identifier: Build and manage unique (fresh) identifiers
  - Ledgrid: Constants Some global constant definitions, for fine-tuning
  - ListExtra: Additional features for the standard module List
  - Memo: Module for building memoised functions
  - Oomarshal: Object-oriented marshalling support
  - PreludeExtra: "Additional features" for the standard module Pervasives
  - Shell: A collection of (mainly quick and easy) wrappers for the most
 famous Unix tools and generic unix commands or scripts
  - StrExtra: Additional features for the standard library Str
  - Sugar: Basic shortcuts and syntactic sugar
  - SysExtra: Additional features for the standard module Sys
  - UnixExtra: Additional features for the standard library Unix
  - Widget: Some generic tools for building GUIs
  - Wrapper: Handling shell scripts in OCaml