Force loading of shards configuration when asking for environments

Closes GH-88
Closes GH-94
Fix rails2 spec failure
Reload connection before executing #update_column method

It delegates to .update_all, so we need to set the Proxy's connection
to the correct shard explicitly.
Only wrap ActiveRecord-related objects in ScopeProxy
Test any? method
Merge pull request #125 from ragalie/update_column

Reload connection before executing #update_column method
Merge pull request #126 from ragalie/fix_rails2_spec

Fix rails2 spec failure
Merge pull request #127 from ragalie/fix_scope_proxy

Only wrap ActiveRecord-related objects in ScopeProxy
Properly check equality between sharded AR objects

Modifies ActiveRecord::Base#== to check that #current_shard is equal
(in addition to current #== functionality). Delegates ScopeProxy#==
to @klass.
Deprecates .octopus_* methods on AR::Base

Overloads .establish_connection, .set_table_name and .table_name=
instead.
Merge pull request #131 from ragalie/establish_connection

Deprecates .octopus_* methods on AR::Base
Merge pull request #130 from ragalie/equality

Properly check equality between sharded AR objects
Only run any? specs on rails3
Merge pull request #129 from ragalie/fix-any-spec

Only run any? specs on rails3