Schema upgraded to version 2

Hashes are moved own table.
Normalization and possible faster hashing.
Fixed double primary key
Updated SQL queries for new Schema

Closes #5
Added function to get sha id
Added function to add hash table entries
Updated add function to use new schema

Closes #7
Added constructor for easy struct creation
Updated tests for new schema
Added test for identical files with different paths
Fixed getSHAid not working
Added function to query pHash for path
Fixed getSHAid
Added tests for getSHAid
Fixed copy-paste error for getSHAid
Using cunstructor to compact test
Modified update SHA for new schema
Merge branch 'master' into schema_upgrade
Added check for empty sha rows
Fixed SQL statements
Updated schema with separate sha and phash tables