Merge master changes into db branch.

Refactor flags, add option to dump from one database connection to another.

Merge commit '135f33d9ea' into db

# Conflicts:
#	spec/database_spec.cr
#	src/sqlite3/lib_sqlite3.cr
#	src/sqlite3/result_set.cr
#	src/sqlite3/statement.cr

spec/connection_spec.cr

@@ -0,0 +1,47 @@
+require "./spec_helper"
+
+private def dump(source, target)
+  source.using_connection do |conn|
+    conn = conn.as(SQLite3::Connection)
+    target.using_connection do |backup_conn|
+      backup_conn = backup_conn.as(SQLite3::Connection)
+      conn.dump(backup_conn)
+    end
+  end
+end
+
+describe Connection do
+  it "opens a database and then backs it up to another db" do
+    with_db do |db|
+      with_db("./test2.db") do |backup_db|
+        db.exec "create table person (name string, age integer)"
+        db.exec "insert into person values (\"foo\", 10)"
+
+        dump db, backup_db
+
+        backup_name = backup_db.scalar "select name from person"
+        backup_age = backup_db.scalar "select age from person"
+        source_name = db.scalar "select name from person"
+        source_age = db.scalar "select age from person"
+
+        {backup_name, backup_age}.should eq({source_name, source_age})
+      end
+    end
+  end
+
+  it "opens a database, inserts records, dumps to an in-memory db, insers some more, then dumps to the source" do
+    with_db do |db|
+      with_mem_db do |in_memory_db|
+        db.exec "create table person (name string, age integer)"
+        db.exec "insert into person values (\"foo\", 10)"
+        dump db, in_memory_db
+
+        in_memory_db.scalar("select count(*) from person").should eq(1)
+        in_memory_db.exec "insert into person values (\"bar\", 22)"
+        dump in_memory_db, db
+
+        db.scalar("select count(*) from person").should eq(2)
+      end
+    end
+  end
+end

spec/driver_spec.cr

@@ -1,17 +1,5 @@
 require "./spec_helper"
 
-DB_FILENAME = "./test.db"
-
-def with_db(&block : DB::Database ->)
-  DB.open "sqlite3:#{DB_FILENAME}", &block
-ensure
-  File.delete(DB_FILENAME)
-end
-
-def with_mem_db(&block : DB::Database ->)
-  DB.open "sqlite3://%3Amemory%3A", &block
-end
-
 def sql(s : String)
   "#{s.inspect}"
 end

spec/spec_helper.cr

@@ -2,3 +2,23 @@ require "spec"
 require "../src/sqlite3"
 
 include SQLite3
+
+DB_FILENAME = "./test.db"
+
+def with_db(&block : DB::Database ->)
+  File.delete(DB_FILENAME) rescue nil
+  DB.open "sqlite3:#{DB_FILENAME}", &block
+ensure
+  File.delete(DB_FILENAME)
+end
+
+def with_db(name, &block : DB::Database ->)
+  File.delete(name) rescue nil
+  DB.open "sqlite3:#{name}", &block
+ensure
+  File.delete(name)
+end
+
+def with_mem_db(&block : DB::Database ->)
+  DB.open "sqlite3://%3Amemory%3A", &block
+end