Added README file which explains a little about the makefile structure.

doc/README.makefiles

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+PURPOSE :  To explain the makefile system in firebird2.
+
+STATUS:  Still a work in progress (both the makefiles, and this document)
+
+AUTHORS: Mark O'Donohue mark.odonohue@luduwg.edu.au
+
+COPYRIGHT: All rights retained by authors.
+           For distribution with Firebird source
+           (Someone who knows this legal stuff will update it later)
+
+OVERVIEW
+
+The new makefiles were created to fit in with autoconf, to place the object
+files in seperate directories to the source files and to simplify the build
+process.
+
+It really does rely on using gnu make so that is the best version to use.
+
+
+THE REALLY QUICK INTRO
+
+For linux this is how I do a compile (classic is only one currently)
+
+./configure 
+$cd src
+$make > make.log 2>&1 ; cat make.log | grep -v warning > make2.log ; vi make2.log
+
+For an install checkout 
+
+$make install
+
+it will list your options - but also needs some work.
+
+
+MAKEFILE
+
+Makefiles are found in src/make.new 
+
+make.rules
+make.defaults
+make.shared.variables
+
+prefix.xxx (where xxx = platform)
+
+In src/make.new there are a number of Makefile.in.xxx files and some make.xxx 
+
+
+STRUCTURE OF MAKEFILE.IN.XXX
+
+
+Each Makefile.in.xxx has the following somewhere near the top:
+
+include make.rules
+include make.defaults
+include make.platform
+include make.shared.variables
+
+...
+...
+
+
+These are:
+
+make.rules 
+
+This contains the default rules for compiling the system components.  Such as
+directory macros CXX etc.  
+
+
+make.defaults
+
+This contains default values for macros that it is likely that the user may
+want to override.
+
+
+make.platform
+
+This file is created from the prefix.xxx where xxx=linux/darwin/freebsd etc.  
+It provides a spot for the user to override or repalce macros that have been
+defined in make.rules and make.defaults.  In addition extra dependancies can
+be added to build extra targets.
+
+
+make.shared.variables
+
+This file contains the defintion of macros that are shared across all of the 
+modules.  The only set that are needed are those files that are contained in
+the libgds.a/so library since files from many modules contribute to the library.
+
+
+
+CREATING OBJECT FILES
+
+ 
+In the makefiles the object files are of two sorts .o static and .lo 
+which are suitable for shared libraries.  On most systems the source 
+files need to be compiled twice to create both .o and .lo files.  F
+Fortunately the program libtool can help work with this.
+
+The general format of .o file dependancies is:
+
+SERVER_Sources = server.cpp
+SERVER_Objects = $(SERVER_Sources:%.cpp=$(OBJ)/%.o)
+
+
+So the .o files live in $(OBJ) where:
+OBJ = $(ROOT)/gen/$ModuleName 
+
+
+Each Makefile also specifies an AllObjects and Dependancies macro which 
+identified all the objects that this Makefile is to create and the name
+of the dependency files generated for those objects.
+
+AllObjects = $(Alice_Objects) 
+
+
+FILE DEPENDANCIES
+
+Include file dependancy information is automatically generated by the gcc
+compiler.
+
+The gcc compiler has a flag -MMD which will generate in addition to the
+.o file a .d file which contains the dependancy chain of #includes required
+for the program.  These are then edited and stored in the $(OBJ) directory and
+are included in the bottom line of the makefile with
+
+Dependencies = $(All_Objects:.o=.d) 
+
+include $(Dependancies)