[maintenance] minor fixes debian snap (dashpay#152)

* build - snap, update documentation to be conform to listing page

* build - debian, fix missing files

* travis - add snapcraft.yaml to lint whitespace whitelist

* snap, add required whitespaces

contrib/devtools/lint-whitespace.sh

@@ -31,14 +31,14 @@ if [ -z "${TRAVIS_COMMIT_RANGE}" ]; then
 fi
 
 showdiff() {
-  if ! git diff -U0 "${TRAVIS_COMMIT_RANGE}" -- "." ":(exclude)depends/patches/" ":(exclude)src/leveldb/" ":(exclude)src/secp256k1/" ":(exclude)src/univalue/" ":(exclude)doc/release-notes/"; then
+  if ! git diff -U0 "${TRAVIS_COMMIT_RANGE}" -- "." ":(exclude)depends/patches/" ":(exclude)src/leveldb/" ":(exclude)src/secp256k1/" ":(exclude)src/univalue/" ":(exclude)doc/release-notes/" ":(exclude)snap/snapcraft.yaml"; then
     echo "Failed to get a diff"
     exit 1
   fi
 }
 
 showcodediff() {
-  if ! git diff -U0 "${TRAVIS_COMMIT_RANGE}" -- *.cpp *.h *.md *.py *.sh ":(exclude)src/leveldb/" ":(exclude)src/secp256k1/" ":(exclude)src/univalue/" ":(exclude)doc/release-notes/"; then
+  if ! git diff -U0 "${TRAVIS_COMMIT_RANGE}" -- *.cpp *.h *.md *.py *.sh ":(exclude)src/leveldb/" ":(exclude)src/secp256k1/" ":(exclude)src/univalue/" ":(exclude)doc/release-notes/" ":(exclude)snap/snapcraft.yaml"; then
     echo "Failed to get a diff"
     exit 1
   fi

share/pixmaps/ion16.xpm

@@ -0,0 +1,72 @@
+/* XPM */
+static char * ion16_xpm[] = {
+"16 16 53 1",
+" 	c None",
+".	c #0D1229",
+"+	c #0D122A",
+"@	c #0E142C",
+"#	c #0E142D",
+"$	c #0E152E",
+"%	c #0F1731",
+"&	c #101833",
+"*	c #101935",
+"=	c #0D132B",
+"-	c #0F1630",
+";	c #111B38",
+">	c #111C3B",
+",	c #ADB0BB",
+"'	c #E6E8EB",
+")	c #747A8C",
+"!	c #FFFFFF",
+"~	c #FEFEFF",
+"{	c #101A36",
+"]	c #121D3B",
+"^	c #FDFDFD",
+"/	c #152345",
+"(	c #142244",
+"_	c #4C5670",
+":	c #142346",
+"<	c #15254A",
+"[	c #16274C",
+"}	c #9198A8",
+"|	c #9096A6",
+"1	c #152447",
+"2	c #172A51",
+"3	c #182B54",
+"4	c #F6F6F7",
+"5	c #202945",
+"6	c #192D57",
+"7	c #1A305C",
+"8	c #206C9D",
+"9	c #142143",
+"0	c #238CC0",
+"a	c #238BBF",
+"b	c #15264C",
+"c	c #238CC1",
+"d	c #1C426F",
+"e	c #238BC0",
+"f	c #D4D6DC",
+"g	c #444C63",
+"h	c #303D5C",
+"i	c #36415D",
+"j	c #BABEC8",
+"k	c #122041",
+"l	c #2D3651",
+"m	c #FEFEFE",
+"n	c #D9DBE0",
+".....+@##@+.....",
+"...+$%&**&%$+...",
+"..=-*;>,')!~-=..",
+".+-{]!^/(_!!{-+.",
+".$*]!:<[[<}|!*$.",
+"+%;!1[2332[:45%+",
+"@&]!<267862<9!&@",
+"#*!![3700a3[(!*#",
+"#*!!b370ca3[(!*#",
+"@&>!<26de62<9!&@",
+"+%;!:[2332[:fg%+",
+".$*]!:<[[<hi!*$.",
+".+-{]!j((k!!{-+.",
+"..=-*;lm!n!!-=..",
+"...+$%&**&%$+...",
+".....+@##@+....."};