Fix some compilation warnings

There were warnings about nested $ifthen structures and stray names
with spurious commas in symbol declarations.

(cherry picked from commit 132360e3)

Backbone.gms

@@ -88,7 +88,7 @@ $eolcom //
 $onempty   // Allow empty data definitions
 
 * Output file streams
-files log /''/, gdx, f_info /'%output_dir%/info.txt'/;
+Files log /''/, gdx /''/, f_info /'%output_dir%/info.txt'/;
 
 * Include options file to control the solver
 $include '%input_dir%/1_options.gms';

inc/1c_parameters.gms

@@ -25,7 +25,8 @@ Scalars
     continueLoop "Helper to stop the looping early"
     currentForecastLength "Length of the forecast in the curren solve, minimum of unchanging and decreasing forecast lengths"
     count "General counter"
-    count_lambda, count_lambda2 "Counter for lambdas"
+    count_lambda
+    count_lambda2 "Counter for lambdas"
     count_sample "Counter for samples"
     cum_slope "Cumulative for slope"
     cum_lambda "Cumulative for lambda"

inc/3c_inputsLoop.gms

@@ -416,12 +416,12 @@ loop(effLevelGroupUnit(effLevel, effGroup, unit)${  mSettingsEff(mSolve, effLeve
 * --- Input data processing ---------------------------------------------------
 * =============================================================================
 
-$ifthen defined scenario
+$ifthen.scenarios defined scenario
 * --- Scenario reduction ------------------------------------------------------
 if(active(mSolve, 'scenred') and mSettings('schedule', 'scenarios') > 1,
     $$include 'inc/scenred.gms'
 );
-$endif
+$endif.scenarios
 
 * --- Update probabilities ----------------------------------------------------
 Option clear = p_msft_probability;