When adding a new file here:

 * Name it S??-x, where x is the (new) library you plan to support and
   ?? is a two-digit number between 00 and 99.

 * The name x consists of capital letters and digits only.

 * The number ?? indicates the (increasing) order in which compiler
   options are added to the compiler call; the smaller this number,
   the earlier the options appear. For linker options, this order is
   reversed.

 * Pay attention: If the name of a package x is a prefix of the name
   of another package y, then x should appear before y in the
   (increasing) order. For instance, GMP has number 20 which is
   smaller than the number 21 of GMPXX.

 * Each file is lists a set of flags to enable support for a certain
   3rd party library. In our terminology, such a file is called a
   package, whereas the libraries are referred to as features. A
   package may provide any number of features. Vice versa, a feature
   may be provided by several packages; however, only one of the
   packages providing a feature may actually be used at the same time,
   that is, packages providing the same feature are implicitly in
   conflict to each other.

   Each file has the following entries.

   - PROVIDES: the feature(s) provided by it, separated by spaces.

   - DESCRIPTION: text, only used to distinguish from other packages
       which provide the same feature(s).

   - CXXFLAGS: compiler flags 

   - LDFLAGS: linker flags 

   - LIBS: list of libraries to link with, separated by spaces.

   - REQUIRES: list of features and/or variables required by the
     package. A required variable is prefixed by the string DOLLAR_,
     whereas features appear as-is. A package should only depend on
     features that appear before it in the (increasing) order of
     packages.

   - INCOMPATIBLE: list of features and/or variables incompatible with
     the package. An incompatible variable is prefixed by DOLLAR_,
     features appear as-is.

   - STDINCLDIRS: list of directories (separated by :) which may be
     package include dir (may contain wildcards, if
     backslash-escaped).

   - INCLTHING: a directory or file which has to be in the package
     include dir (may contain wildcards, if backslash-escaped). This
     is used to identify candidate dirs only.

   - STDLIBDIRS: list of directories (separated by :) which may be
     package lib dir (may contain wildcards, if backslash-escaped).

   - LIBTHING: a directory or file which has to be in the package lib
     dir (may contain wildcards, if backslash-escaped). This is used
     to identify candidate dirs only.
     
* Each feature should have a test program called test_name.C, where
name is the name of the feature. There are no test programs for
packages.

# EOF