Several improvements.
List of new files

new file:   src/master/address_book.cc
new file:   src/master/address_book.hh
new file:   src/master/address_book_page.cc
new file:   src/master/address_book_page.hh
new file:   src/master/scheduler.cc
new file:   src/master/scheduler.hh
Merge branch 'master' of github.com:vicentebolea/MRR