Handle null value

Should handle null value here, or promotions usage limit should not be nullable.
[CoreBundle] Fix order of bundles in Kernel
Merge pull request #2062 from stloyd/patch-2

[CoreBundle] Fix order of bundles in Kernel
Remove CMF dependency from CoreBundle
[ContentBundle] Updated CMF version
Fix #2055; php error in ShippingCountryRuleChecker if no country selected
Update state machine

Fix callback args overriding
Enable back softdeleteable filter
Merge pull request #2072 from winzou/update-state-machine

Update state machine
Merge pull request #2073 from winzou/filter

Enable back softdeleteable filter in OrderRepository
[Product] Add missing changes after rebase
Merge pull request #2074 from stloyd/bugfix/api_product

[Product] Add missing changes after rebase
[CoreBundle] Enable back softdeleteable filter for users repository

Otherwise you can't view user details in backend.
Merge pull request #2067 from crevillo/issue-2055

Fix #2055; php error in ShippingCountryRuleChecker if no country selected
[AddressBundle] Don't validate province if no country was set
Merge pull request #2075 from stloyd/patch-2

[CoreBundle] Enable back softdeleteable filter for users repository
Merge pull request #2065 from saidul/issue_2063

[CoreBundle] Remove CMF dependency from CoreBundle
Don't make ajax request for provinces if contry value is empty
Merge pull request #2059 from MichaelMackus/promotion-handle-null-usage-limit

Handle null value
Update liipimaginebundle 1.0 completed