first pass at linear solver doc

tools/doc/DoxygenLayout.xml

@@ -73,7 +73,7 @@
       <privatestaticmethods title=""/>
       <privateattributes title=""/>
       <privatestaticattributes title=""/>
-      <friends title=""/>
+      <friends visible="no" title=""/>
       <related title="" subtitle=""/>
       <membergroups visible="yes"/>
     </memberdecl>

tools/doc/cpp_linear.doxy

@@ -494,7 +494,7 @@ HIDE_UNDOC_MEMBERS     = NO
 # has no effect if EXTRACT_ALL is enabled.
 # The default value is: NO.
 
-HIDE_UNDOC_CLASSES     = NO
+HIDE_UNDOC_CLASSES     = YES
 
 # If the HIDE_FRIEND_COMPOUNDS tag is set to YES, doxygen will hide all friend
 # (class|struct|union) declarations. If set to NO, these declarations will be
@@ -908,7 +908,7 @@ IMAGE_PATH             =
 # need to set EXTENSION_MAPPING for the extension otherwise the files are not
 # properly processed by doxygen.
 
-INPUT_FILTER           = "python3 tools/doc/doxygen_filter.py"
+INPUT_FILTER           =
 
 # The FILTER_PATTERNS tag can be used to specify filters on a per file pattern
 # basis. Doxygen will compare the file name with each pattern and apply the
@@ -2049,7 +2049,7 @@ INCLUDE_FILE_PATTERNS  =
 # recursively expanded use the := operator instead of the = operator.
 # This tag requires that the tag ENABLE_PREPROCESSING is set to YES.
 
-PREDEFINED             = USE_CBC USE_SCIP
+PREDEFINED             = USE_CBC USE_SCIP USE_GLOP USE_BOP USE_CLP
 
 # If the MACRO_EXPANSION and EXPAND_ONLY_PREDEF tags are set to YES then this
 # tag can be used to specify a list of macro names that should be expanded. The