Add sharing of groups between databases

* Add source folder keeshare for sharing with corresponding define WITH_XC_KEESHARE
* Move common crypto parts to src/crypto/ssh
* Extended OpenSSHKey
* Move filewatching to own file (currently in two related classes DelayedFileWatcher and BulkFileWatcher)
* Small improvements for style and code in several classes
* Sharing is secured using RSA-Keys which are generated on demand
* Publisher signs the container using their private key
* Client can verify the signed container and choose to decline an import,
import only once or trust the publisher and automatically import all
data of this source henceforth
* Integration of settings into Group-Settings, Database-Settings and Application-Settings
* Introduced dependency QuaZip as dependency to allow combined export of
key container and the (custom format) certificate

src/core/Entry.cpp

@@ -955,6 +955,20 @@ QString Entry::maskPasswordPlaceholders(const QString& str) const
     return result;
 }
 
+Entry* Entry::resolveReference(const QString& str) const
+{
+    QRegularExpressionMatch match = EntryAttributes::matchReference(str);
+    if (!match.hasMatch()) {
+        return nullptr;
+    }
+
+    const QString searchIn = match.captured(EntryAttributes::SearchInGroupName);
+    const QString searchText = match.captured(EntryAttributes::SearchTextGroupName);
+
+    const EntryReferenceType searchInType = Entry::referenceType(searchIn);
+    return m_group->database()->resolveEntry(searchText, searchInType);
+}
+
 QString Entry::resolveMultiplePlaceholders(const QString& str) const
 {
     return resolveMultiplePlaceholdersRecursive(str, ResolveMaximumDepth);