[usermanual] Make sure URLs to external HTML files aren't getting .php appended

(cherry picked from commit dfba841ea80431c93c177d469fb8c47d2506dc5e)
Add the Pentax *ist DL2 do rawspeed

(cherry picked from commit c388431dab0cba35c57ac0afb1ba77fd1aeac1b4)
Diferent black points for samsung NX1 high iso

(cherry picked from commit 9e7592f5dfc727a120d8ea93869b6207acaef178)
Fix reference of wb_presets.c in POFILES.in.

(cherry picked from commit 78e41d011c3991855ccf14b168dda2ccd18b8eb4)
wb_presets: fix 7D Mark II (#10243)