Enable configurable 'maxBatchChanges' limit

One use case is when a group is responsible for importing
large batches of changes delivered from external partners,
and those changes all require review. This group, and only
this group, should be allowed to bypass the limit that is
enforced for everyone else.

Allow site administrators to configure the 'maxBatchChanges'
limit for users from global capability UI of All-Projects
access. The min box does not make sense if its value is not 0,
so disable it after giving it the default value of 0.

The effective limit value will be the capability value if it
exists, or the value in gerrit.config if it exists, or else
no limit.

Change-Id: Ic929dc4a89cc8ccbd098035ce2ceac4f22fd54da
Tidy up code style in CapabilitiesIT

Import global capability names explicitly.

Fix some minor code style issues.

Change-Id: I66a9eb95fe44cd96f05bc7aa2e629e9bff93baf8
Remove unused generateHttpPassword from CapabilityInfo

The "Generate HTTP Password capability was removed in
change Id907cc103591eed029fd08af700bb1bb6a618ff8 but this
was missed.

Change-Id: I28b3bcc09b9d52079d2a7301a38f7f8de7b7d4f2
Tidy up global capability definitions

Move MODIFY_ACCOUNT to correct alphabetical order.

Rename DEFAULT_MAX_BATCH_CHANGES to DEFAULT_MAX_BATCH_CHANGES_LIMIT,
and move it up so it's right after BATCH_CHANGES_LIMIT. This makes it
consistent with the way DEFAULT_MAX_QUERY_LIMIT is defined.

Change-Id: Ie71a7a5886f95a50e9dae25ba16b3717e2ce27a7
Fix granting of capabilities in capabilities acceptance test

Do not grant ADMINISTRATE_SERVER and PRIORITY for User.

Set the default ranges for range permissions.

Change-Id: I5e653bfc288d62a0f342b06af28eabeaa45c9b43
Fix capabilities acceptance test broken by batch changes limit

This was missed before in Ic929dc4 and the acceptance tests are
currently broken:
  FAILURE testCapabilitiesUser: batchChangesLimit
  java.lang.NoSuchFieldException: batchChangesLimit

Add handling of the batch changes limit field in the acceptance
test.

Change-Id: I486864594cbccaaf0a6f14f14c0b5bc7107e580d