update authors/contributors list

these additions were made based on scanning commit authors since the
last update, at the time of the 1.1.4 release.

COPYRIGHT

@@ -25,6 +25,7 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 Authors/contributors include:
 
+Alexander Monakov
 Anthony G. Basile
 Arvid Picciani
 Bobby Bingham
@@ -32,12 +33,18 @@ Boris Brezillon
 Brent Cook
 Chris Spiegel
 Clément Vasseur
+Denys Vlasenko
 Emil Renner Berthing
+Felix Fietkau
+Felix Janda
+Gianluca Anzolin
 Hiltjo Posthuma
 Isaac Dunham
 Jens Gustedt
 Jeremy Huntwork
+Joakim Sindholt
 John Spencer
+Josiah Worcester
 Justin Cormack
 Luca Barbato
 Luka Perkov
@@ -54,6 +61,7 @@ Solar Designer
 Stefan Kristiansson
 Szabolcs Nagy
 Timo Teräs
+Trutz Behn
 Valentin Ochs
 William Haddon