[8.0] Port the module 'account_move_template' to the new API

This PR contains the module ***account_move_template*** ported to the new API.
Test and installation seems to me ok.

Let's see what will be the TravisCI response and your reviews :wink: 
Thanks @guewen!
To be sure having undestood your comment properly, could you please review the following lines?

```
    @api.multi
    def lines(self, line_number, computed_lines=None):
        import pdb; pdb.set_trace()
        if computed_lines is None:
            computed_lines = {}
        if computed_lines[line_number] is not None:
            return computed_lines[line_number]
        line = self._get_template_line(line_number)
        if re.match(r'L\( *' + str(line_number) + r' *\)', line.python_code):
            raise exceptions.Warning(
                _('Line %s can\'t refer to itself') % str(line_number)
            )
        try:
            recurse_lines = partial(self.lines, computed_lines=computed_lines)
            computed_lines[line_number] = eval(
                line.python_code.replace('L', 'recurse_lines')
            )
        except KeyError:
            raise exceptions.Warning(
                _('Code "%s" refers to non existing line') % line.python_code)
        return computed_lines[line_number]

    @api.multi
    def compute_lines(self, input_lines):
        # input_lines: dictionary in the form {line_number: line_amount}
        # returns all the lines (included input lines)
        # in the form {line_number: line_amount}
        if len(input_lines) != self._input_lines():
            raise exceptions.Warning(
                _('Inconsistency between input lines and '
                  'filled lines for template %s') % self.name
            )
        computed_lines = self._generate_empty_lines()
        computed_lines.update(input_lines)
        for line_number in computed_lines:
            computed_lines[line_number] = self.lines(
                line_number, computed_lines)
        return computed_lines
```
Thank you in advance.