Updated Windows build guide with more realistic set of pre-requisites.
Updated libboost version listed in Windows build guide to match UNIX guide.
Rewrote libboost installation docs for Windows to match a more conventional process.
Added details of where include and library files should be installed for Windows build process.
Corrected configuration line for Dogecoin to one which is likely to work in a MinGW environment.
Added "pkg-config" to dependencies for Ubuntu/Debian environments..
Documentation for Fedora dependency equivalents.
Added build environment pre-requisites for Fedora build instructions.
Merge pull request #375 from rnicoll/1.7-dev_windows_build_doc

Update Windows and Fedora build guides