Enable/disable foreign key constraings for sqlite.

[gleb-sternharz]

Issue #1447

[qiangxue]

Could you update the CHANGELOG file accordingly? Thanks.

[gleb-sternharz]

Done.

[cebe]

As stated in #1447 this is not supported by older sqlite versions, we need to make sure it does not break applications using old sqlite versions.

[resurtm]

And of course, unit tests as always are very welcome! ;-)

[resurtm]

Merged manually: 33763f8

[resurtm]

@cebe:

we need to make sure it does not break applications using old sqlite versions

It won't. This case is unit tested (1b24643).

[cebe]

It won't. This case is unit tested (1b24643).

@resurtm also with sqlite < 3.7.10 ?

[resurtm]

@cebe, i did some tests on PHP 5.2 (sqlite 3.3.7) and on PHP 5.4 (sqlite 3.7.7.1):

1. Testing script: http://pastebin.com/dBngz3CA
2. PHP 5.2 (sqlite 3.3.7): http://pastebin.com/6uYMNGZ5
3. PHP 5.4 (sqlite 3.7.7.1): http://pastebin.com/q3X3vyDa

Looks good to me. Btw, note that default sqlite version bundled with the latest PHP 5.2 is 3.3.7—our unit tests are all right.

[cebe]

Okay, cool :) Thanks for the effort!