[twig] independet twig service for email templates.
[doc] custom_loader option removed.
send email form.
clean code. add back convert flat vars array to nested array.
Merge pull request #8 from makasim/send-email-form

Send email form
[form]Fixes to sendEmailType
Merge pull request #9 from makasim/send-email-form

[form]Fixes to sendEmailType
fix __toString() on AdminTemplate
fix some code styles, remove LifecycleCallbacks definition.
add content type to email template.
allow set text and html body.
remove setter\getter for ContentType.
[form] add body html field to SendEmailType form type.
Merge pull request #11 from makasim/form-send-email-add-body-html

[form] add body html field to SendEmailType form type.
Merge pull request #10 from makasim/email-template-add-content-type

Email bodyHtml template.
Update README.markdown
better requirements of vendors.