Add generic InteractionGadget implementation.

Use of meta types is deprecated. Ignoring them makes it possible to optimize
getTypeBasedMethod thanks to portal types as classes.

- New readOnlyTransactionCache context manager replacing
  enableReadOnlyTransactionCache and disableReadOnlyTransactionCache
- Drop compatibility code that tolerate a dummy context to be passed to
  getReadOnlyTransactionCache and getTransactionalVariable.

Catch "ready" event and call form update.

This way many handlers can bind to it (use idea of document.ready in DOM world).

This reverts commit ddcb5001.

This commit itself is good. But some more work is needed to
check failures that were hidden

In poppler 0.18+, pdftohtml generates " " instead of " ", so
make sure both are accepted.

_getOb() is too low level and is no longer called by Zope during traversal (which uses
__getitem__()), if the object is not an explicity subobject.

__getitem__() is the right interface for a folder to pretend to have objects it
doesn't actually have.

same as bcc12a28 (use getattr to be compatible with newer zope version).

since Zope 2.12.23, ObjectManager's get and __getitem__ returns only 'items' (no attributes / methods from the class or from acquisition).

since Zope 2.12.23, ObjectManager's get and __getitem__ returns only 'items' (no attributes / methods from the class or from acquisition).

testERP5WebWithDms will pass now as librsvg is well installed now and
assertion on tests were simplied to become more reliable (it provides
less false positives for image comparation).

The functional test testSurchargeWithInvalidDateTime was improved for
better assertions.

This fixes test_getInstancePropertyAndBaseCategoryList
and also removes obsolete 'updatePropertySheetDefinitionDict' methods.

This reverts commit 51d40d1e.

Use colors can generate little diferences at the outcome comparations
between the computers, so black and white is enough for the test purpose,
to compare if the background image is showed or not.

fix svg definition as in some images the namespace is not
well defined by using xmlns="http://www.w3.org/2000/svg" instead
of xmlns:svg="http://www.w3.org/2000/svg"

Those are the cases of the images generated from OO to SVG conversions.

The image comparation isn't advanced enough to identify minor color
 changes when convert to grey scale. So use simpler images to make
sure we do not get false positives.

The goal of image comparation is only for make sure background is
placed at the figures.