There is no need to edit the CodeBlocks source to get VS2015 working, everything can be done with adding settings. Only if you want to add VS2015 "nicely" so that it can auto-detect the paths and gets a nicer name it requires code changes, otherwise you can just create a copy from the VS2010 compiler and make the changes yourself.
Lets start with your main issue, the error parser. All these settings go into Settings -> Compiler -> Global compiler settings | [your selected compiler] | Tab Other Settings -> Advanced Options | Tab Output parsing. You need do add some entries to the Parsing expressions list, order DOES MATTER.
Add the following entries AT START of the list to grab the new info messages:
Description: Compiler info
Type: Info
Regular expression: ([][{}() \t#%$!~[:alnum:]&_:+/\.-]+)\(([0-9]+)\)[ \t]*:[ \t]([Nn]ote:[ \t].*)
Sub-expression indices:
Message: 3
Additional message 2: 0
Additional message 3: 0
Filename: 1
Line: 2
Description: Compiler info no line
Type: Info
Regular expression: ([][{}() \t#%$!~[:alnum:]&_:+/\.-]+)[ \t]*:[ \t]([Nn]ote:[ \t].*)
Sub-expression indices:
Message: 2
Additional message 2: 0
Additional message 3: 0
Filename: 1
Line: 0
Modify the regular expression of the following two already present entries:
Parsing Expression "Compiler warning":
Regular expression: ([][{}() \t#%$!~[:alnum:]&_:+/\.-]+)\(([0-9]+)\)[ \t]*:[ \t]([Ww]arning[ \t].*)
Parsing Expression "Compiler error":
Regular expression: ([][{}() \t#%$!~[:alnum:]&_:+/\.-]+)\(([0-9]+)\)[ \t]*:[ \t](.*[Ee]rror[ \t].*)
To detect the new warning messages without line add the following entry directly below "Compiler warning":
Description: Compiler warning no line
Type: Warning
Regular expression: ([][{}() \t#%$!~[:alnum:]&_:+/\.-]+)[ \t]*:[ \t]([Ww]arning[ \t].*)
Sub-expression indices:
Message: 2
Additional message 2: 0
Additional message 3: 0
Filename: 1
Line: 0
Bonus: If you are also using mt.exe in Post-Commands to embed the Manifest into the EXE and want to catch its errors because stupid Windows 10 again blocked write access to the file or whatever, you can add the following entry at the end of the list:
Description: Manifest error
Type: Error
Regular expression: mt.exe[ \t]*:[ \t]*(.*)
Sub-expression indices:
Message: 1
Additional message 2: 0
Additional message 3: 0
Filename: 0
Line: 0
These entries should catch all notes/warnings/errors VS2015 produces, it might miss some linker errors, im getting these only rarely so i don't know if there are any that don't work with the old expressions.
But to sucessfully compile i think your are missing some directories in your search paths, for the compiler you should also need
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt
and for the linker
C:\Program Files (x86)\Windows Kits\10\lib\10.0.10240.0\ucrt\x86
Directory names might differ in the version and architecture part.
@oBFusCATed: Sorry but i don't know where these settings are done in code and don't have time atm to look for that