Before this commit, if the effect function would throw, then the cleanup
function would not be properly assigned, which caused additional errors
later, when the cleanup code would try to call it.
closes#1149
This means that unrelated ids (eg the id of a template, variable or key)
not longer share the same incrementing counter, meaning that you no
longer see a variable named "v2" unless another variable "v1" was
generated previously, this is also true for block data.
Before this commit, when defining a getter in the env passed to useSubEnv,
the value was read, losing the definition of the property.
After this commit, declaring a getter in the env works as expected:
the property stays a getter.
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.
Géry Debongnie