added a java doc style comment for scanner function
completed the java doc style comment for Calculator class
Add comment javadoc into AffixConverter
Add more comment to AffixConverter
Add javadoc to BasicMathsMethods
Add back author
Add comment java doc into the class of ParserFactory
add some comment javadoc into ExpressionTree class (tmr continue)
add java doc to ExpressionTree
add java doc to TreeNode
Adding new JavaDoc with pattern information
Merge commit '73735eaf9f8c65532baa746731508ad221117ff9' into develop

Conflicts:
	src/cal/BasicMathsMethods.java