fix hazard export
fix hg when some rupture does not produce shaking
updated qa (regression) tests with new data and fixed the seed generation
use more meaningful iteration variable name
improved variable naming and docs
Updated tests, updated ref to get_gmfs_per_site
tests/export/hazard_test:

Fixed a broken scenario hazard export test.
tests/export/hazard_test:

Removed a false comment.
Merge pull request #1081 from larsbutler/scenario-export-fix

Fix a broken scenario hazard export test

[r=micheles] [f=*trivial]
massaging code
Merge branch 'master' of https://github.com/gem/oq-engine into fix-1144388
massaging codebase
Updated function to get gmvs per site and spatial correlation tests
updated expected values precision
Merge pull request #1074 from matley/fix-1144388

Fix 1144388
Merge branch 'master' of https://github.com/gem/oq-engine into fix-1144741
moved MAX/MIN_SINT_32 in models
Merge pull request #1083 from gem/correlation_model_qa_tests

Correlation model qa tests
Merge pull request #1075 from matley/fix-1144741

Fix 1144741