Remove README inaccuracy, where does not allow multiple arguments

Documented the case-insensitive nature of the match feature.

Documenting the library's behavior. People and other libraries (cf. Squeel) have come to depend on this behavior, and so am submitting this pull request to specify it authoritatively.

Closes #189

"Relational DataBase Management systems",

Conflicts:
	History.txt

Remove deleted file by 9cbfc8 from gemspec

Rails is not testing against this version so even if arel works we can't
guarantee people application will

Add :encode_with to sql_literal for proper YAML serialization

Deprecations

Remove deprecated calls to `update` with preference to using `compile_update` and then calling `to_sql` on the resulting object to execute the SQL

Remove deprecated calls to `insert` with preference to using `compile_insert` and then calling `to_sql` on the resulting object to execute the SQL

Remove deprecated calls to `delete` with preference to using `compile_delete` and then calling `to_sql` on the resulting object to execute the SQL

Remove deprecated

Support `columns_for_distinct` with Oracle adapter

Cache visitor dispatch on a per-visitor basis

Improve performance of #uniq across a large number of nodes

Closes #197