(cherry picked from commit ef6c151e)

This is necessary to ensure that Octave Forge packages are loaded.
(cherry picked from commit fd633cba)

(cherry picked from commit b8b7d90e)

Closes: #222
(cherry picked from commit c2c88600)

(cherry picked from commit cc26a1d8)

- fix support for filenames with extension (.m, .mat, .xls), since the manual
  and the bison grammar both support it
- fix support for XLS files under Octave
- add support for XLSX files
- run test for loading XLS files
(cherry picked from commit 2f9e34c5)

preprocessor: add @#ifndef directive(cherry picked from commit 20f2c176)

(cherry picked from commit b7b50fa9)

fixed bug with options mode_compute=0,mode_file=....
added tests for mode_compute=4 and mode_compute=6. They increase computing time of the
test suite by about 30 minutes.

(cherry picked from commit e75b18f9)

(cherry picked from commit 78693d97)

(cherry picked from commit 25d59148)

(cherry picked from commit d7a3504b)

(cherry picked from commit 97388517)

(cherry picked from commit 43d13fda)

(cherry picked from commit 78d9cb92)

Bug fix: graphic options are not passed to global options_ (for the next release try to skip the use of the global here).
(cherry picked from commit e835c7d9)

(manual cherry-pick from c031b463)

(cherry picked from commit cb34c870)

(cherry picked from commit 906f5328)

This reverts commit fcceec89.
(cherry picked from commit dd8f16c8)

(cherry picked from commit fcceec89)

(cherry picked from commit 560771be)

(cherry picked from commit 285e40eb)

This should fix some random crashes of the preprocessor
(cherry picked from commit dd0190bb)

(manually cherry picked from commit 3e612e02)

(cherry picked from commit 5b1ecaf6)

(cherry picked from commit 868afeb9)

e637319b
and
16fa6efc

If parameter values want to violate BK conditions, optimizer can bounce and get to a local optimum.
If there is true problem with killing unit roots, estimation will crash anyhow.

(cherry picked from commit 5d5771a8)

(cherry picked from commit 6cfec3f6)

(cherry picked from commit df26c668)

(cherry picked from commit e67d3d3f)

(cherry picked from commit c5842456)

(cherry picked from commit 08f7c61e)

    fixed bug with deterministic exogenous variables at order==2 (moved
    all relevant code to stochastic_solvers.m)