Consider only unique variables in stoch_simul
Consider only unique members of varlist in estimation
Adds new option to select which variables to consider for estimation

First step for ticket #336
Convert use of unique to be compatible with older Matlab version
reporting: fix assertion
Fix test for availability of xlswrite.
Upgrade the minimum requirement to MATLAB 7.5 (R2007b).
fix bug introduced in 4caa36232b647da91710af34f7d10786415ef776
Exit gracefully if an external function name is used as a model local variable.

Closes #599
Merge pull request #607 from JohannesPfeifer/unique_varlist

Unique varlist and choosing endogenous variables for estimation
Fix typo.
Add new options consider_all_endogenous and consider_only_observed.

Closes #336
Fix typo.
reporting: check passed values
Add missing semicolon.
Remove bad_cond_flag argument from solve1.

This flag was not grounded on any solid theoretical foundation.

This commit actually makes solve_algo=2 to be exactly the same than solve_algo=4.
Add trust-region nonlinear solver.

Closes #260
Add warning if prior allows for negative variances and if negative estimated variances are encountered. Closes #522

Due to the use of variances for Sigma_e and subsequently backing out the standard deviation from these variances, the sign of the standard deviation does not matter and no bound needs to be imposed.
reporting, dates: make shiftS calls more efficient
reporting: simplify code