Bump version to 0.28.7 and add a release note

Summary: The release note is related to D15080.

Test Plan:
  ninja print-version
Read the release notes.

Reviewers: #bitcoin_abc, PiRK

Reviewed By: #bitcoin_abc, PiRK

Differential Revision: https://reviews.bitcoinabc.org/D15126

CMakeLists.txt

@@ -7,7 +7,7 @@ set(CMAKE_USER_MAKE_RULES_OVERRIDE
 )
 
 project(bitcoin-abc
-	VERSION 0.28.6
+	VERSION 0.28.7
 	DESCRIPTION "Bitcoin ABC is a full node implementation of the eCash protocol."
 	HOMEPAGE_URL "https://www.bitcoinabc.org"
 )

contrib/aur/bitcoin-abc-qt/PKGBUILD

@@ -1,7 +1,7 @@
 # Maintainer: Josh Ellithorpe <quest@mac.com>
 
 pkgname=bitcoin-abc-qt
-pkgver=0.28.6
+pkgver=0.28.7
 pkgrel=0
 pkgdesc="Bitcoin ABC with bitcoind, bitcoin-cli, bitcoin-tx, bitcoin-seeder and bitcoin-qt"
 arch=('i686' 'x86_64')

contrib/aur/bitcoin-abc/PKGBUILD

@@ -1,7 +1,7 @@
 # Maintainer: Josh Ellithorpe <quest@mac.com>
 
 pkgname=bitcoin-abc
-pkgver=0.28.6
+pkgver=0.28.7
 pkgrel=0
 pkgdesc="Bitcoin ABC with bitcoind, bitcoin-tx, bitcoin-seeder and bitcoin-cli"
 arch=('i686' 'x86_64')

doc/release-notes.md

@@ -1,7 +1,10 @@
-# Bitcoin ABC 0.28.6 Release Notes
+# Bitcoin ABC 0.28.7 Release Notes
 
-Bitcoin ABC version 0.28.6 is now available from:
+Bitcoin ABC version 0.28.7 is now available from:
 
-  <https://download.bitcoinabc.org/0.28.6/>
+  <https://download.bitcoinabc.org/0.28.7/>
 
-This is a maintenance release with no user-visible change.
+This release includes the following features and fixes:
+ - Prevent stalling the block downloads by dynamically adjusting the timeout.
+   This will help syncing the blockchain when the network connection speed is
+   low.

doc/release-notes/release-notes-0.28.6.md

@@ -0,0 +1,7 @@
+# Bitcoin ABC 0.28.6 Release Notes
+
+Bitcoin ABC version 0.28.6 is now available from:
+
+  <https://download.bitcoinabc.org/0.28.6/>
+
+This is a maintenance release with no user-visible change.