Add Makefile.
Do not throw an exception if var or loop doesn't exist

Simply replace this var or loop with an empty string.
Fix a bug with TMPL_LOOP and TMPL_IF last inner text segment.

A last inner text segment is disappeared from a compiled template.
Add autotests.
Add some autotests for TMPL_LOOP.
Add a convertion from float to list and from integer to list.

If in a supplied to htmltmpl:apply/2 data some variable contain float
or integer instead of a string, we do a convertion to a string.

Attention! Use floats with a care! 7.0 float is converted to
"7.00000000000000000000e+00" string.
Add autotests for float and integer convertions.
Add a removing of htmltmpl.beam and test.beam to clean target.
Fix warnings about unused variables.
Add some more autotests.
Align autotest statuses.
Replace some code in apply functions with lists:keyfind/3.