Improvement of db_helper for sqlite support

[goyalpramod]

Earlier db_helper for sqlite support was storing the temporary db in the root directory. After this PR it will store the temporary db files in a temporary directory that can be deleted later.

Regex has also been improved in create_schema_for_db to take care of the case when semi-colon (;) may be present inside the query.

[goyalpramod]

@suyashgautam kindly review the changes whenever you get the time

[suyashgautam]

Merge this code as part of #53 Hence closing this ticket

[suyashgautam]

Merge this code as part of #53 Hence closing this ticket