Correctly generate bigint primary keys in sqlite.

generate bigint primary keys correctly. Autoincrement cannot be set as
it only works with INTEGER columns[1]. I decided to use some string
manipulations as the entire SQL generation bits are a bit janky and I've
already re-written them for 3.0.

[1] https://www.sqlite.org/autoinc.html

Closes #cakephpGH-1552

lib/Cake/Model/Datasource/Database/Sqlite.php

@@ -407,10 +407,19 @@ public function buildColumn($column) {
 			return null;
 		}
 
-		if (isset($column['key']) && $column['key'] === 'primary' && $type === 'integer') {
+		$isPrimary = (isset($column['key']) && $column['key'] === 'primary');
+		if ($isPrimary && $type === 'integer') {
 			return $this->name($name) . ' ' . $this->columns['primary_key']['name'];
 		}
-		return parent::buildColumn($column);
+		$out = parent::buildColumn($column);
+		if ($isPrimary && $type === 'biginteger') {
+			$replacement = 'PRIMARY KEY';
+			if ($column['null'] === false) {
+				$replacement = 'NOT NULL ' . $replacement;
+			}
+			return str_replace($this->columns['primary_key']['name'], $replacement, $out);
+		}
+		return $out;
 	}
 
 /**

lib/Cake/Test/Case/Model/Datasource/Database/SqliteTest.php

@@ -264,6 +264,17 @@ public function testBuildColumn() {
 		$result = $this->Dbo->buildColumn($data);
 		$expected = '"huge" bigint(20) NOT NULL';
 		$this->assertEquals($expected, $result);
+
+		$data = array(
+			'name' => 'id',
+			'type' => 'biginteger',
+			'length' => 20,
+			'null' => false,
+			'key' => 'primary',
+		);
+		$result = $this->Dbo->buildColumn($data);
+		$expected = '"id" bigint(20) NOT NULL PRIMARY KEY';
+		$this->assertEquals($expected, $result);
 	}
 
 /**