Merge pull request #604 from rattoma/4.4

HP-filtered moments: Fix bug when unit root models provide NaN's or Inf's in g_omega
removed useless test with exist() that is very expensive in
Octave (but apparently not in Matlab)

(cherry picked from commit c1e0d68351527153960a988087abcc316e2b17ff)
Fixed bug. Closes #591.
(cherry picked from commit 5f46f983c13e21c52358667913ed1b84a6a374d2)
Fixed bug. Closes #590.
(cherry picked from commit 4254da0a0080df66cb99a662d020e8ed0230a5f0)
Mention in the manual that a subsample can be created out of a dseries object using the overloaded parenthesis. Closes #589.
(cherry picked from commit 681b194cbef5ab3e3f7479d5615e1478c46f26ee)
Filter out use of loglinear with simulated moments

Does not work because steady state is not logged
(cherry picked from commit dfd9e3819bfe1577926b231f8847c0ee2efdbdb8)
Fix option loglinear for stoch_simul.m by also logging steady state.

Must be done to assure correct simulations and output of moments. Cannot be done in the solver itself as estimation performs logging of steady state also outside of solver
(cherry picked from commit 3da8e92aa55c4e4ffe447085090c1aad99d8c78a)
Clarify the role of the loglinear option for stoch_simul
(cherry picked from commit 6575d5ab5e2a8b2640ed369f0105dbdf67858038)
Make sure repeated runs of stoch_simul.m with loglinear option do not crash due to logged steady state
(cherry picked from commit 15f0353d0221609d5dc0afaf268f8470cb9b1bb5)
Add unit test for loglinear option
(cherry picked from commit 9885a31587b01272e5b18554aa3c9d82d5e7ac77)
Make sure that estimation works after loglinear option in stoch_simul with initval-block

stoch_simul logs the steady state. Here, it is transformed back
(cherry picked from commit 4bd7f4952a94db027c6fc1a6ed6451b46b4468bf)
Check if the steady state is strictly positive when simulating/estimating a model with loglinear option.
(cherry picked from commit 62aa9b8fa537498375269552c84180a05e2091a4)
Clarify prefilter option in estimation
(cherry picked from commit e054c5c322d47aede0978bfd97b89c33977f1901)
Document treatment of missing observations
Closes #286
(cherry picked from commit 2c36898dc494c916e80b872ab0e88c837a321f7d)
Provide more information on the loglinear option and its data treatment
(cherry picked from commit 5db6a4a0c4b1c376e743c8c8bd79148a159808fc)
Remove constant and noconstant options from manual for estimation command

Those options are set internally depending on whether the steady state is zero or not. See http://www.dynare.org/pipermail/dev/2014-January/003655.html
(cherry picked from commit 5626b0cb89f0647fade3dbe641b02f924e802972)
Filter out inconsistent specification of prefiltering when observation equation is not mean zero
(cherry picked from commit d82252e805c007a99de353e49d1a3fa2f961d748)
Issue an error message if loglinear option is equal to 1 in non linear likelihood routine.
(cherry picked from commit 00cfec8fb6ce4a37c7bfb6e72cd5119a0d1b1b09)
Rewrote the error message issued when the prefilter option in used while the steady state of the observed variables is non zero (introduced in commit d82252e805c007a99de353e49d1a3fa2f961d748).
(cherry picked from commit 7864e0ec82dcc944013e997a552d31cb533eebfe)
Fixed typo (write @cite{} instead of \cite{} for citations in texinfo).
(cherry picked from commit ebf4d2a9a601843fb07c9077d0471ff47456eb3f)