Delete view in View handler

Signed-off-by: Kévin Lesénéchal <kevin@lesenechal.org>
WppTplEngine: add accesors to class Block

Signed-off-by: Kévin Lesénéchal <kevin@lesenechal.org>
WppTplEngine: add destructor to Blocks::For

Signed-off-by: Kévin Lesénéchal <kevin@lesenechal.org>
WppTplEngine: add destructor to class Expr

Signed-off-by: Kévin Lesénéchal <kevin@lesenechal.org>
WppTplEngine: add destructor to class Blocks::Inherit

Signed-off-by: Kévin Lesénéchal <kevin@lesenechal.org>
WppTplEngine: InheritBlock: detach parent

Signed-off-by: Kévin Lesénéchal <kevin@lesenechal.org>
WppTplEngine: Inherit: clear parent childs

Signed-off-by: Kévin Lesénéchal <kevin@lesenechal.org>
WppTplEngine: delete root block

Signed-off-by: Kévin Lesénéchal <kevin@lesenechal.org>