Before this commit, portal was a Component, now is a directive.
This commit also clean some unused code, and fix an issue on the clean
optimization when a portal is found in a condition or a loop.
The slot inner working has been reworked. A prop "slots" is now passed
explicitely to the component. It looks like
{ slotName_1: slotInfo_1, ..., slotName_m: slotInfo_m }
with the objects slotInfo_i with mandatory keys "__render", "__ctx",
and optional key "__scope" and possibly others.
Here is how a slotInfo object can be created:
A slotInfo object is normally created by setting in a template something
like
<div>
<t t-set-slot="foo" t-set-scope="scope" param_1="var" param_2="3">
content
<t t-esc="scope.bool"/>
<t t-esc="scope.num"/>
</t>
</div>
and it will be used somewhere like
<div>
<t t-esc="props.slots.foo.param_1"/>
<t t-slot="foo" bool="other_var" num="5">
</div>
In the above example, the function "__render" produces the block dom
element for the content of the t-set-slot.
The context "__ctx" will have a key "scope" with value { bool: ..., num: 5 }
and "__scope" will be set to "scope".
t-out automatically escaped content when it is a string not marked
with the `markup` function
t-out renders the raw content if it is a Block, or if it has been marked
with the `markup` funtion.
t-esc has been kept since it is safe and is optimized to render text nodes.
all t-raw calls are in fact the same as t-out.
Jorge Pinna Puissant