Matlab warnings when running BirthDeath example

[dweindl]

>> generateLNA('BirthDeath/BirthDeath.xml', 'BirthDeath', 'BOTH');
Warning: Support of character vectors will be removed in a future release. Character vectors can be used only for variable names and numbers.
Instead, to create symbolic expressions first create symbolic variables using 'syms'. To evaluate character vectors and strings representing
symbolic expressions, use 'str2sym'. 
> In sym>convertExpression (line 1581)
  In sym>convertChar (line 1486)
  In sym>tomupad (line 1236)
  In sym (line 215)
  In cell2sym (line 31)
  In SBML2StoichProp (line 59)
  In generateLNA (line 14) 
[... many more as above ... ]
> In sym>convertExpression (line 1581)
  In sym>convertChar (line 1486)
  In sym>tomupad (line 1236)
  In sym (line 215)
  In sym/subs>@(x)sym(x) (line 206)
  In sym/subs>normalize (line 206)
  In sym/subs>mupadsubs (line 154)
  In sym/subs (line 142)
  In SBML2StoichProp (line 65)
  In generateLNA (line 14) 
Warning: Function 'Theta' not verified to be a valid MATLAB function. 
Warning: Function 'phi' not verified to be a valid MATLAB function. 
Computing symbolic derivatives
Warning: Solutions are valid under the following conditions: in((k_m*k_p^2 + g_m*k_p^2*phi01 + g_m^2*k_p*phi01 + g_m*g_p^2*phi02 +
g_m^2*g_p*phi02 + g_m*g_p*k_p*phi01)/(g_m*g_p*(g_m + g_p)), 'real') & in((k_p*(k_m + g_m*phi01))/(g_m*(g_m + g_p)), 'real') & in((k_m +
g_m*phi01)/g_m, 'real'). To include parameters and conditions in the solution, specify the 'ReturnConditions' value as 'true'. 
> In solve>warnIfParams (line 508)
  In solve (line 357)
  In generateLNAComponents>solveSS_var (line 377)
  In generateLNAComponents (line 109)
  In generateLNA (line 25) 
computing initial sensitivities

[dweindl]

Warning: Support of character vectors will be removed in a future release. Character vectors can be used only for variable names and numbers.
Instead, to create symbolic expressions first create symbolic variables using 'syms'. To evaluate character vectors and strings representing
symbolic expressions, use 'str2sym'.

Should follow that advice at some point, but would break pre-2017B compatibility now.