1) Added a calculation="cc". This computes the (estimated) q+G=0 contribution to the bare and screened KC corrections.
   A report on this quantities is printed on output and can be used to correct a posteriori a calculation performed 
   without any corrective scheme (l_vcut=.false.) 
2) Restructure solve_linter_koop_mod.f90. Now it call common routines in LR_modules (sternheimer_kernel). 
   Now the option "fix_orb" does not work anymore. It should be integrated in sternheimer_kernel. Not a big 
   deal because 1) we never use it 2) should be very easy to re-implement
3) Add example03 that show how to use kcwpp_interp.x and kcwpp_sh.x
4) Update example01 with a better wannierization for the empty states. 
5) New way of writing partial results for the relaxed KC corrections. Now the entire contribution (i.e. the bare <ni|f_Hxc|ni> 
   plus the response part <ni|f_Hxc \Chi f_Hxc |ni> is printed on output. Before only the response part was printed). This 
   is totally equivalent to the previous version, but makes it simpler to handle the correction for the g+G=0 terms.
   Example' references updated consequently
6) Added the code to simulate UPS in KCW/PP. See PRL Phys. Rev. Lett. 114, 166405 for details
