Added exercises to chapter 1
Added exercises to chapter 2
Added exercises to ch3.php
Added exercises to ch4
Merge branch 'ch02' into dev_1.0
Merge branch 'ch03' into dev_1.0
Merge branch 'ch04' into dev_1.0
Added exercises to ch5
Added exercises to ch6
Added forms, php files to ch07
Added database sample code file
added: ch10 exercises
Added forms and graphics code
Added files for ch11
Added files for ch12
Added files for ch13
Added php script to ch14
Merge branch 'ch01' into dev_1.0
Merge branch 'ch10' into dev_1.0
Merge branch 'ch11' into dev_1.0