Merge pull request #1 from os3dna/nick

added introduction chapter
Added Chapter for Semantic Wec : RDF
Branch creation
XQuery chapter finished
RegExp chapter finished
Added Chapter for Semantic Web : RDF
Merge pull request #2 from os3dna/Alex

Alex
Merge branch 'master' into nick
Added images folder
Merge pull request #3 from os3dna/Alex

Added images folder
Merge branch 'master' into nick
Added my final version for Semantic Web : RDF
Footnotes added
Merge pull request #4 from os3dna/diana

Diana
conflict resolution
merged master