Add take/drop, move jdbc stuff, document default of postgres

Add take and drop functionality to the queries, so now you can use the take and
drop functions in a similar way to how they work on seqs in clojure.

Move jdbc interface stuff into clojure-sql.jdbc, so if you're using jdbc you
can include it yourself. (If you're not using jdbc then it shouldn't bother
you).

Given the default compilation target is actually postgres, document that.

1 files changed, 5 insertions, 3 deletions

diff --git a/README.md b/README.md
index 74c63bb..ad7ae3d 100644
--- a/README.md
+++ b/README.md
@@ -20,7 +20,7 @@ allow for data to be inserted, updated and deleted.
 queries is performed by multimethods which dispatch on an arbitrary
 (and otherwise unused) `db` parameter. This allows the compilation of
 queries to be entirely special-cased per database. By default
-`clojure-sql` will produce standard ANSI SQL.
+`clojure-sql` will produce SQL for PostgreSQL.
 
 ## Usage
 
@@ -39,8 +39,10 @@ queries to be entirely special-cased per database. By default
                 '(= :uid :pid))
         (s/project [:username]))
     ; => ["SELECT \"u\".\"username\" FROM \"users\" AS \"u\" JOIN \"people\" AS \"p\" ON (\"u\".\"id\" = \"p\".\"id\") WHERE (\"p\".\"fname\" = ?)" "Henry")]
-    
-    (s/use-jdbc! "postgres://user:pass@localhost:5432/db")
+
+    (require '[clojure-sql.jdbc :as jdbc])
+    ; => nil 
+    (jdbc/use-jdbc! "postgres://user:pass@localhost:5432/db")
     ; => nil